stream/src/main/scala/org/apache/pekko/stream/impl/TraversalBuilder.scala (6 lines):
	- line 624: // TODO: Use automatically a linear builder if applicable
	- line 680: // TODO: Remove
	- line 1299: // TODO Optimize Map access
	- line 1350: // TODO Optimize Map access
	- line 1371: // TODO Optimize Map access
	- line 1381: // TODO Optimize Map access


project/SbtMultiJvmPlugin.scala (5 lines):
	- line 42: val jvmOptions = TaskKey[Seq[String]]("jvm-options") // TODO: shouldn't that be regular `javaOptions`?
	- line 72: // TODO fugly workaround for now
	- line 140: // TODO try to make sure that this is only generated on a need to have basis
	- line 158: // TODO there must be a way get at keys in the tasks that I just don't get
	- line 495: // TODO move this out, maybe to the hosts string as well?


stream/src/main/scala/org/apache/pekko/stream/impl/io/TcpStages.scala (4 lines):
	- line 66: // TODO: Timeout on bind
	- line 174: // FIXME: Previous code was wrong, must add new tests
	- line 200: completeStage() // TODO need to manually shut down instead right?
	- line 576: // FIXME: A method like this would make soo much sense on Duration (i.e. toOption)


stream/src/main/scala/org/apache/pekko/stream/impl/fusing/ActorGraphInterpreter.scala (4 lines):
	- line 467: // TODO: add interpreter name back
	- line 581: // TODO: really needed?
	- line 600: // TODO: Fix event limit heuristic
	- line 603: // TODO: Better heuristic here


multi-node-testkit/src/main/scala/org/apache/pekko/remote/testconductor/Player.scala (4 lines):
	- line 265: import context.dispatcher // FIXME is this the right EC for the future below?
	- line 270: // FIXME: Initial capacity should be carefully chosen
	- line 288: // FIXME: Currently ignoring, needs support from Remoting
	- line 299: case _: Done => stay() // FIXME what should happen?


cluster-metrics/src/multi-jvm/scala/org/apache/pekko/cluster/metrics/ClusterMetricsExtensionSpec.scala (4 lines):
	- line 119: // TODO ensure same contract
	- line 133: // TODO ensure same contract
	- line 157: // TODO ensure same contract
	- line 162: // TODO ensure same contract


distributed-data/src/main/scala/org/apache/pekko/cluster/ddata/Replicator.scala (4 lines):
	- line 946: // FIXME #26566: we can change from Option to UniqueAddress after supporting mixed rolling updates for some versions
	- line 950: // FIXME #26566: we can change from Option to Long after supporting mixed rolling updates for some versions
	- line 1144: // FIXME we can change from Option to UniqueAddress after supporting mixed rolling updates for some versions,
	- line 2062: // TODO split it to several DeltaPropagation if too many entries


stream/src/main/scala/org/apache/pekko/stream/javadsl/SubFlow.scala (4 lines):
	- line 624: new SubFlow(delegate.grouped(n).map(_.asJava)) // TODO optimize to one step
	- line 644: new SubFlow(delegate.groupedWeighted(minWeight)(costFn.apply).map(_.asJava)) // TODO optimize to one step
	- line 715: new SubFlow(delegate.sliding(n, step).map(_.asJava)) // TODO optimize to one step
	- line 952: new SubFlow(delegate.groupedWithin(maxNumber, duration).map(_.asJava)) // TODO optimize to one step


stream/src/main/scala/org/apache/pekko/stream/javadsl/SubSource.scala (4 lines):
	- line 615: new SubSource(delegate.grouped(n).map(_.asJava)) // TODO optimize to one step
	- line 635: new SubSource(delegate.groupedWeighted(minWeight)(costFn.apply).map(_.asJava)) // TODO optimize to one step
	- line 706: new SubSource(delegate.sliding(n, step).map(_.asJava)) // TODO optimize to one step
	- line 937: new SubSource(delegate.groupedWithin(maxNumber, duration).map(_.asJava)) // TODO optimize to one step


stream/src/main/scala/org/apache/pekko/stream/javadsl/Flow.scala (4 lines):
	- line 1266: new Flow(delegate.grouped(n).map(_.asJava)) // TODO optimize to one step
	- line 1286: new Flow(delegate.groupedWeighted(minWeight)(costFn.apply).map(_.asJava)) // TODO optimize to one step
	- line 1361: new Flow(delegate.sliding(n, step).map(_.asJava)) // TODO optimize to one step
	- line 1601: new Flow(delegate.groupedWithin(maxNumber, duration).map(_.asJava)) // TODO optimize to one step


persistence-typed/src/main/scala/org/apache/pekko/persistence/typed/internal/Running.scala (3 lines):
	- line 190: // TODO support from journal to fast forward https://github.com/akka/akka/issues/29311
	- line 273: val (next, doUnstash) = applyEffects(cmd, state, effect.asInstanceOf[EffectImpl[E, S]]) // TODO can we avoid the cast?
	- line 440: // FIXME validate this is the correct sequence nr from that replica https://github.com/akka/akka/issues/29259


stream/src/main/scala/org/apache/pekko/stream/scaladsl/Graph.scala (3 lines):
	- line 776: // FIXME make `PartitionOutOfBoundsException` a `final` class when possible
	- line 788: // FIXME BC add `eagerCancel: Boolean = false` parameter
	- line 816: val out: Seq[Outlet[T]] = Seq.tabulate(outputPorts)(i => Outlet[T]("Partition.out" + i)) // FIXME BC make this immutable.IndexedSeq as type + Vector as concrete impl


remote/src/main/scala/org/apache/pekko/remote/artery/compress/InboundCompressions.scala (3 lines):
	- line 263: final val KeepOldTablesNumber = 3 // TODO could be configurable
	- line 475: // TODO expensive, check if building the other way wouldn't be faster?
	- line 533: // TODO optimised somewhat, check if still to heavy; could be encoded into simple array


remote/src/main/scala/org/apache/pekko/remote/artery/aeron/ArteryAeronUdpTransport.scala (3 lines):
	- line 185: // TODO: Add FR events
	- line 276: // TODO Add FR Events
	- line 310: // TODO: Note that the AssociationState.controlStreamIdleKillSwitch in control stream is not used for the


remote/src/main/scala/org/apache/pekko/remote/RemoteDaemon.scala (3 lines):
	- line 176: log.debug("does not accept deployments (untrusted) for [{}]", path) // TODO add security marker?
	- line 248: // TODO RK currently the extracted “address” is just ignored, is that okay?
	- line 249: // TODO RK canonicalize path so as not to duplicate it always #1446


remote/src/main/scala/org/apache/pekko/remote/artery/compress/TopHeavyHitters.scala (3 lines):
	- line 157: // TODO possibly can be optimised further? (there is a benchmark)
	- line 218: // TODO: This will probe the *whole* table all the time for non-entries, there is no option for early exit.
	- line 219: // TODO: Maybe record probe lengths so we can bail out early.


actor/src/main/scala/org/apache/pekko/actor/FSM.scala (3 lines):
	- line 287: // TODO: Can be removed once we can break State#timeout signature to `Option[Duration]`
	- line 831: // TODO Use context.watch(actor) and receive Terminated(actor) to clean up list
	- line 836: // TODO Use context.watch(actor) and receive Terminated(actor) to clean up list


actor/src/main/scala/org/apache/pekko/actor/ActorPath.scala (2 lines):
	- line 309: toString.compareTo(r.toString) // FIXME make this cheaper by comparing address and name in isolation
	- line 468: // TODO RK investigate Phil’s hash from scala.collection.mutable.HashTable.improve


stream/src/main/scala/org/apache/pekko/stream/scaladsl/Compression.scala (2 lines):
	- line 32: * FIXME: should strategy / flush mode be configurable? See https://github.com/akka/akka/issues/21849
	- line 58: * FIXME: should strategy / flush mode be configurable? See https://github.com/akka/akka/issues/21849


stream/src/main/scala/org/apache/pekko/stream/ActorMaterializer.scala (2 lines):
	- line 616: * FIXME: this is used for all kinds of buffers, not only the stream actor, some use initial some use max,
	- line 766: Attributes.CancellationStrategy.Default :: // FIXME: make configurable, see https://github.com/akka/akka/issues/28000


remote/src/main/scala/org/apache/pekko/remote/artery/Codecs.scala (2 lines):
	- line 599: .runNextActorRefAdvertisement() // TODO: optimise these operations, otherwise they stall the hotpath
	- line 603: .runNextClassManifestAdvertisement() // TODO: optimise these operations, otherwise they stall the hotpath


cluster/src/main/scala/org/apache/pekko/cluster/ClusterHeartbeat.scala (2 lines):
	- line 59: // TODO log the sequence nr once serializer is enabled
	- line 253: // TODO: log response time and validate sequence nrs once serialisation of sendTime is released


stream/src/main/scala/org/apache/pekko/stream/impl/fusing/Ops.scala (2 lines):
	- line 1506: // TODO more optimisations can be done here - prepare logOnPush function etc
	- line 1626: // TODO more optimisations can be done here - prepare logOnPush function etc


actor/src/main/scala/org/apache/pekko/actor/TypedActor.scala (2 lines):
	- line 198: // TODO implement writeObject and readObject to serialize
	- line 199: // TODO Possible optimization is to special encode the parameter-types to conserve space


persistence/src/main/scala/org/apache/pekko/persistence/Persistent.scala (2 lines):
	- line 139: def deleted: Boolean // FIXME deprecate, issue #27278
	- line 144: def sender: ActorRef // FIXME deprecate, issue #27278


stream/src/main/scala/org/apache/pekko/stream/stage/GraphStage.scala (2 lines):
	- line 802: // FIXME `onClose` is a poor name for `onComplete` rename this at the earliest possible opportunity
	- line 837: // FIXME `onClose` is a poor name for `onComplete` rename this at the earliest possible opportunity


remote/src/main/scala/org/apache/pekko/remote/artery/compress/CompressionTable.scala (2 lines):
	- line 46: // TODO: these are some expensive checks, about the numbers being consecutive, without gaps
	- line 47: // TODO: we can remove them, make them re-map (not needed I believe though)


persistence-typed/src/main/scala/org/apache/pekko/persistence/typed/state/internal/DurableStateStoreInteractions.scala (2 lines):
	- line 39: // FIXME use CircuitBreaker here, that can also replace the RecoveryTimeout
	- line 87: // FIXME These hook methods are for Telemetry. What more parameters are needed? persistenceId?


cluster-sharding-typed/src/main/scala/org/apache/pekko/cluster/sharding/typed/delivery/ShardingProducerController.scala (2 lines):
	- line 103: @ApiMayChange // TODO #28719 when removing ApiMayChange consider removing `case class` for some of the messages
	- line 314: // TODO maybe there is a need for variant taking message extractor instead of ShardingEnvelope


project/Dependencies.scala (2 lines):
	- line 189: // TODO remove from "test" config
	- line 212: // TODO check if `l ++=` everywhere expensive?


multi-node-testkit/src/main/scala/org/apache/pekko/remote/testconductor/Conductor.scala (2 lines):
	- line 512: case _: Done => // FIXME what should happen?
	- line 604: // TODO what happens with the other waiting players in case of a test failure?


build.sbt (2 lines):
	- line 176: // TODO pekko-persistence dependency should be provided in pom.xml artifact.
	- line 322: // .settings(OSGi.persistenceTck) TODO: we do need to export this as OSGi bundle too?


remote/src/main/scala/org/apache/pekko/remote/artery/tcp/ArteryTcpTransport.scala (2 lines):
	- line 233: // TODO Possible performance improvement, could we reduce the copying of bytes?
	- line 422: // TODO perhaps a few more things can be extracted and DRY with AeronUpdTransport.runInboundOrdinaryMessagesStream


actor-typed/src/main/scala/org/apache/pekko/actor/typed/internal/LoggerClass.scala (2 lines):
	- line 39: // TODO use stack walker API when we no longer need to support Java 8
	- line 71: // TODO: can potentially guard for ClassNotFoundException, but seems unlikely


distributed-data/src/main/scala/org/apache/pekko/cluster/ddata/ORMultiMap.scala (2 lines):
	- line 240: * TODO add implicit after deprecated is EOL.
	- line 268: * TODO add implicit after deprecated is EOL.


remote/src/main/java/org/apache/pekko/remote/artery/compress/CountMinSketch.java (2 lines):
	- line 157: if (o instanceof ActorRef) { // TODO possibly scary optimisation
	- line 161: // TODO it should be thought over if this preciseness (just a random number, and not


actor/src/main/scala/org/apache/pekko/dispatch/VirtualThreadSupport.scala (2 lines):
	- line 68: // TODO support replace scheduler when we drop Java 8 support
	- line 107: // TODO lookup.findClass is only available in Java 9


stream/src/main/scala/org/apache/pekko/stream/impl/fusing/GraphInterpreter.scala (2 lines):
	- line 250: // FIXME: This calculates the maximum size ever needed, but most assemblies can run on a smaller queue
	- line 470: // TODO: deadlock detection


actor/src/main/scala/org/apache/pekko/dispatch/AbstractDispatcher.scala (2 lines):
	- line 319: // TODO check whether this should not actually be a property of the mailbox
	- line 483: case "array"       => ThreadPoolConfig.arrayBlockingQueue(size, false) // TODO config fairness?


remote/src/main/scala/org/apache/pekko/remote/transport/netty/NettyTransport.scala (2 lines):
	- line 503: override def isResponsibleFor(address: Address): Boolean = true // TODO: Add configurable subnet filtering
	- line 505: // TODO: This should be factored out to an async (or thread-isolated) name lookup service #2960


actor/src/main/scala/org/apache/pekko/actor/FaultHandling.scala (2 lines):
	- line 56: // FIXME How about making ChildRestartStats immutable and then move these methods into the actual supervisor strategies?
	- line 674: context.stop(child) // TODO optimization to drop child here already?


actor/src/main/scala/org/apache/pekko/dispatch/Mailboxes.scala (2 lines):
	- line 172: // TODO remove in Akka 2.3
	- line 228: // TODO RK remove these two for Akka 2.3


remote/src/main/scala/org/apache/pekko/remote/artery/aeron/AeronSink.scala (2 lines):
	- line 146: // TODO: Identify different sinks!
	- line 205: // FIXME does calculation belong here or in impl?


distributed-data/src/main/scala/org/apache/pekko/cluster/ddata/PNCounterMap.scala (2 lines):
	- line 121: * TODO add implicit after deprecated is EOL.
	- line 129: * TODO add implicit after deprecated is EOL.


cluster-sharding-typed/src/main/scala/org/apache/pekko/cluster/sharding/typed/ClusterShardingSettings.scala (2 lines):
	- line 98: leastShardAllocationRebalanceThreshold = settings.tuningParameters.leastShardAllocationRebalanceThreshold, // TODO extract it a bit
	- line 693: leastShardAllocationRebalanceThreshold = classic.leastShardAllocationRebalanceThreshold, // TODO extract it a bit


project/Paradox.scala (2 lines):
	- line 75: // TODO page not linked to
	- line 81: // FIXME https://github.com/lightbend/paradox/issues/350


actor/src/main/scala/org/apache/pekko/japi/JavaAPI.scala (2 lines):
	- line 288: seq.foreach(l.add) // TODO could be optimised based on type of Seq
	- line 298: // TODO in case we decide to pull in scala-java8-compat methods below could be removed - https://github.com/akka/akka/issues/16247


project/StreamOperatorsIndexGenerator.scala (2 lines):
	- line 89: // FIXME document these methods as well
	- line 214: "| |Operator|Description|\n" ++ // TODO mini images here too


persistence/src/main/scala/org/apache/pekko/persistence/fsm/PersistentFSMBase.scala (2 lines):
	- line 512: // TODO Use context.watch(actor) and receive Terminated(actor) to clean up list
	- line 517: // TODO Use context.watch(actor) and receive Terminated(actor) to clean up list


remote/src/main/scala/org/apache/pekko/remote/Endpoint.scala (2 lines):
	- line 765: // FIXME remove these counters when tuning/testing is completed
	- line 815: // FIXME remove this when testing/tuning is completed


persistence/src/main/scala/org/apache/pekko/persistence/journal/leveldb/SharedLeveldbStore.scala (2 lines):
	- line 48: // TODO it would be nice to DRY this with AsyncWriteJournal, but this is using
	- line 74: // TODO it would be nice to DRY this with AsyncWriteJournal, but this is using


stream/src/main/scala/org/apache/pekko/stream/impl/PhasedFusingActorMaterializer.scala (2 lines):
	- line 126: // FIXME why do we need a global unique name for the child?
	- line 719: // TODO: bail on unknown types


cluster/src/multi-jvm/scala/org/apache/pekko/cluster/NodeChurnSpec.scala (1 line):
	- line 132: // FIXME issue #21483


stream/src/main/scala/org/apache/pekko/stream/scaladsl/Source.scala (1 line):
	- line 187: // FIXME: Out => Unit should stay, right??


stream/src/main/scala/org/apache/pekko/stream/impl/Transfer.scala (1 line):
	- line 81: // FIXME: This is completely unnecessary, refactor MapFutureProcessorImpl


actor/src/main/scala/org/apache/pekko/dispatch/BatchingExecutor.scala (1 line):
	- line 80: unbatchedExecute(current) // TODO what if this submission fails?


cluster/src/multi-jvm/scala/org/apache/pekko/cluster/MultiDcClusterSpec.scala (1 line):
	- line 144: // FIXME This is already part of the cluster, is this intended? Joined on line 107


distributed-data/src/main/scala/org/apache/pekko/cluster/ddata/protobuf/ReplicatorMessageSerializer.scala (1 line):
	- line 503: // TODO ownerAddress is only needed for PruningInitialized, but kept here for


bench-jmh/src/main/scala/org/apache/pekko/stream/InterpreterBenchmark.scala (1 line):
	- line 50: // FIXME: This should not be here, this is pure setup overhead


actor/src/main/scala-2.13/org/apache/pekko/util/ByteString.scala (1 line):
	- line 813: * TODO: Add performance characteristics


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/Effect.scala (1 line):
	- line 210: * FIXME what about events scheduled through the scheduler?


remote/src/main/scala/org/apache/pekko/remote/artery/aeron/AeronSource.scala (1 line):
	- line 187: // FIXME push calculation to JFR?


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/internal/BehaviorTestKitImpl.scala (1 line):
	- line 132: try Behavior.canonicalize(Behavior.interpretSignal(current, context, PostStop), current, context) // TODO why canonicalize here?


project/TestQuickUntilPassed.scala (1 line):
	- line 44: // TODO Figure out a way to pass input from testQuickUntilPassed into testQuickRecursive


cluster-metrics/src/main/scala/org/apache/pekko/cluster/metrics/ClusterMetricsRouting.scala (1 line):
	- line 314: // TODO read factor from reference.conf


serialization-jackson/src/main/scala/org/apache/pekko/serialization/jackson/StreamRefModule.scala (1 line):
	- line 16: // FIXME maybe move many things to `org.apache.pekko.serialization.jackson.internal` package?


distributed-data/src/main/scala/org/apache/pekko/cluster/ddata/DeltaPropagationSelector.scala (1 line):
	- line 194: // TODO perhaps also remove oldest when deltaCounter is too far ahead (e.g. 10 cycles)


persistence-typed/src/main/scala/org/apache/pekko/persistence/typed/state/javadsl/Effect.scala (1 line):
	- line 47: // FIXME add delete effect


stream/src/main/scala/org/apache/pekko/stream/scaladsl/Tcp.scala (1 line):
	- line 117: // TODO maybe this should be a new setting, like `pekko.stream.tcp.bind.timeout` / `shutdown-timeout` instead?


actor/src/main/scala/org/apache/pekko/io/DnsProvider.scala (1 line):
	- line 24: *  TODO make private and remove deprecated in v1.1.0


stream/src/main/scala/org/apache/pekko/stream/scaladsl/Hub.scala (1 line):
	- line 660: // TODO: Try to eliminate modulo division somehow...


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/scaladsl/TestInbox.scala (1 line):
	- line 75: // TODO expectNoMsg etc


cluster-tools/src/main/scala/org/apache/pekko/cluster/client/ClusterClient.scala (1 line):
	- line 745: // TODO: ADDRESS FOR v.2.5


persistence/src/main/scala/org/apache/pekko/persistence/state/DurableStateStoreRegistry.scala (1 line):
	- line 99: @unused clazz: Class[T], // FIXME generic Class could be problematic in Java


project/PekkoBuild.scala (1 line):
	- line 39: val parallelExecutionByDefault = false // TODO: enable this once we're sure it does not break things


persistence/src/main/scala/org/apache/pekko/persistence/journal/EventAdapters.scala (1 line):
	- line 146: EventSeq(adapters.flatMap(_.fromJournal(event, manifest).events): _*) // TODO could we could make EventSeq flatMappable


actor-typed/src/main/scala/org/apache/pekko/actor/typed/internal/receptionist/LocalReceptionist.scala (1 line):
	- line 70: * @param subscriptionsPerActor current subscriptions per subscriber (needed since a subscriber can subscribe to several keys) FIXME is it really needed?


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/javadsl/TestInbox.scala (1 line):
	- line 77: // TODO expectNoMsg etc


actor/src/main/scala/org/apache/pekko/actor/ActorRef.scala (1 line):
	- line 657: class SerializedDeadLetterActorRef extends Serializable { // TODO implement as Protobuf for performance?


distributed-data/src/main/scala/org/apache/pekko/cluster/ddata/ORMap.scala (1 line):
	- line 401: // TODO can we get rid of these (safe) casts?


serialization-jackson/src/main/scala/org/apache/pekko/serialization/jackson/ActorRefModule.scala (1 line):
	- line 16: // FIXME maybe move many things to `org.apache.pekko.serialization.jackson.internal` package?


cluster/src/main/scala/org/apache/pekko/cluster/CrossDcClusterHeartbeat.scala (1 line):
	- line 351: // TODO unduplicate this with the logic in MembershipState.ageSortedTopOldestMembersPerDc


persistence-typed/src/main/scala/org/apache/pekko/persistence/typed/internal/ExternalInteractions.scala (1 line):
	- line 72: // FIXME check cinnamon is okay with this being null


remote/src/main/scala/org/apache/pekko/remote/transport/ThrottlerTransportAdapter.scala (1 line):
	- line 644: // FIXME: this depletes the token bucket even when no write happened!! See #2825


remote/src/main/scala/org/apache/pekko/remote/artery/SystemMessageDelivery.scala (1 line):
	- line 348: // TODO we might need have to prune old unused entries


stream/src/main/scala/org/apache/pekko/stream/impl/fusing/FlattenConcat.scala (1 line):
	- line 123: push(out, futureSource.next()) // TODO should filter out the `null` here?


actor/src/main/java/org/apache/pekko/dispatch/AbstractBoundedNodeQueue.java (1 line):
	- line 97: // Possible TODO — impl. could be switched to addNode(new Node(value)) if we want to allocate even if full already


cluster-sharding/src/main/scala/org/apache/pekko/cluster/sharding/internal/AbstractLeastShardAllocationStrategy.scala (1 line):
	- line 114: // FIXME #29589, we currently only look at same dc but proxies in other dcs may delay complete as well right now


cluster-typed/src/multi-jvm/scala/org/apache/pekko/cluster/typed/MultiNodeTypedClusterSpec.scala (1 line):
	- line 56: // TODO: Add support for typed to multi node test kit


actor/src/main/scala/org/apache/pekko/dispatch/Dispatchers.scala (1 line):
	- line 269: // FIXME remove this case in Akka 2.4


actor/src/main/scala/org/apache/pekko/util/LockUtil.scala (1 line):
	- line 32: private val switch = new AtomicBoolean(startAsOn) // FIXME switch to AQS


actor/src/main/scala/org/apache/pekko/event/EventBus.scala (1 line):
	- line 197: // FIXME binary incompatible, but I think it is safe to filter out this problem,


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/scaladsl/Effects.scala (1 line):
	- line 100: * FIXME what about events scheduled through the scheduler?


stream/src/main/scala/org/apache/pekko/stream/impl/fusing/StreamOfStreams.scala (1 line):
	- line 645: case Supervision.Restart => onUpstreamFailure(ex) // TODO implement restart?


cluster-sharding-typed/src/multi-jvm/scala/org/apache/pekko/cluster/sharding/typed/ShardedDaemonProcessSpec.scala (1 line):
	- line 117: // FIXME test removing one cluster node and verify all are alive (how do we do that?)


actor-typed/src/main/scala/org/apache/pekko/actor/typed/internal/pubsub/TopicImpl.scala (1 line):
	- line 86: case _                               => throw new IllegalArgumentException() // FIXME exhaustiveness check fails on receptionist listing match


stream/src/main/scala/org/apache/pekko/stream/impl/streamref/StreamRefsMaster.scala (1 line):
	- line 42: // TODO introduce a master with which all stages running the streams register themselves?


actor/src/main/scala/org/apache/pekko/util/TypedMultiMap.scala (1 line):
	- line 105: * FIXME: should it merge, instead?


stream/src/main/scala/org/apache/pekko/stream/impl/Modules.scala (1 line):
	- line 40: // TODO: Amendshape changed the name of ports. Is it needed anymore?


serialization-jackson/src/main/scala/org/apache/pekko/serialization/jackson/JacksonSerializer.scala (1 line):
	- line 187: // TODO issue #27107: it should be possible to implement ByteBufferSerializer as well, using Jackson's


stream/src/main/scala/org/apache/pekko/stream/impl/ActorProcessor.scala (1 line):
	- line 69: // TODO: buffer and batch sizing heuristics


actor/src/main/scala/org/apache/pekko/io/SelectionHandler.scala (1 line):
	- line 299: // FIXME: Add possibility to signal failure of task to someone


actor-typed/src/main/scala/org/apache/pekko/actor/typed/delivery/internal/ProducerControllerImpl.scala (1 line):
	- line 553: // TODO #28721 to reduce number of writes, consider to only StoreMessageConfirmed for the Request messages and not for each Ack


actor/src/main/scala-3/org/apache/pekko/util/ByteString.scala (1 line):
	- line 814: * TODO: Add performance characteristics


remote/src/main/scala/org/apache/pekko/remote/artery/ArteryTransport.scala (1 line):
	- line 834: // TODO we can also add scrubbing stage that would collapse sys msg acks/nacks and remove duplicate Quarantine messages


actor-typed/src/main/scala/org/apache/pekko/actor/typed/delivery/WorkPullingProducerController.scala (1 line):
	- line 109: @ApiMayChange // TODO #28719 when removing ApiMayChange consider removing `case class` for some of the messages


actor-typed/src/main/scala/org/apache/pekko/actor/typed/delivery/DurableProducerQueue.scala (1 line):
	- line 32: @ApiMayChange // TODO #28719 when removing ApiMayChange consider removing `case class` for some of the messages


stream/src/main/scala/org/apache/pekko/stream/snapshot/MaterializerState.scala (1 line):
	- line 80: // FIXME arbitrary timeout


actor/src/main/scala/org/apache/pekko/io/dns/internal/RecordTypeSerializer.scala (1 line):
	- line 25: // TODO other type than ByteStringBuilder? (was used in pekko-dns)


actor/src/main/scala/org/apache/pekko/event/Logging.scala (1 line):
	- line 1749: // TODO when breaking binary compatibility, these marker methods should become baked into LoggingAdapter itself


stream/src/main/scala/org/apache/pekko/stream/impl/FanOut.scala (1 line):
	- line 237: // FIXME: Eliminate re-wraps


cluster-sharding-typed/src/main/scala/org/apache/pekko/cluster/sharding/typed/internal/ClusterShardingImpl.scala (1 line):
	- line 176: // TODO is it possible to avoid the double evaluation of entityId


actor/src/main/java/org/apache/pekko/actor/AbstractScheduler.java (1 line):
	- line 34: // FIXME #26910


cluster/src/main/scala/org/apache/pekko/cluster/Reachability.scala (1 line):
	- line 150: // FIXME: how should we have gotten into this state?


actor/src/main/scala/org/apache/pekko/util/JavaVersion.scala (1 line):
	- line 24: // FIXME replace with Runtime.version() when we no longer support Java 8


stream/src/main/scala/org/apache/pekko/stream/scaladsl/StreamConverters.scala (1 line):
	- line 188: // TODO removing the QueueSink name, see issue #22523


cluster-typed/src/main/scala/org/apache/pekko/cluster/ddata/typed/internal/ReplicatorBehavior.scala (1 line):
	- line 54: // FIXME perhaps add supervisor for restarting, see PR https://github.com/akka/akka/pull/25988


project/SigarLoader.scala (1 line):
	- line 36: // TODO remove Sigar form test:test* classpath, it is provided by Sigar agent.


actor/src/main/java/org/apache/pekko/japi/pf/ReceiveBuilder.java (1 line):
	- line 67: else return new Receive(statements.orElse(empty)); // FIXME why no new Receive(statements)?


stream-typed/src/main/scala/org/apache/pekko/stream/typed/scaladsl/ActorFlow.scala (1 line):
	- line 32: // TODO would be nice to provide Implicits to allow .ask() directly on Flow/Source


stream/src/main/scala/org/apache/pekko/stream/impl/fusing/GraphStages.scala (1 line):
	- line 40: // TODO: Fix variance issues


stream/src/main/scala/org/apache/pekko/stream/javadsl/Source.scala (1 line):
	- line 3338: new Source(delegate.groupedWithin(maxNumber, duration).map(_.asJava)) // TODO optimize to one step


bench-jmh/src/main/scala/org/apache/pekko/remote/artery/compress/InvertCompressionTableBenchmark.scala (1 line):
	- line 25: TODO: Possibly specialise the inversion, it's not in hot path so not doing it for now


actor-typed/src/main/scala/org/apache/pekko/actor/typed/ActorRef.scala (1 line):
	- line 122: * FIXME doc


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/scaladsl/BehaviorTestKit.scala (1 line):
	- line 58: // FIXME it is weird that this is public but it is used in BehaviorSpec, could we avoid that?


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/javadsl/TestProbe.scala (1 line):
	- line 275: // FIXME awaitAssert(Procedure): Unit would be nice for java people to not have to return null


cluster-tools/src/main/scala/org/apache/pekko/cluster/singleton/ClusterSingletonManager.scala (1 line):
	- line 1184: // TODO we could retry


project/JdkOptions.scala (1 line):
	- line 32: // FIXME replace with Runtime.version() when we no longer support Java 8


actor/src/main/scala/org/apache/pekko/actor/AbstractActor.scala (1 line):
	- line 282: // TODO In Pekko 1.1.0, we can remove deprecation and make the method final


stream/src/main/scala/org/apache/pekko/stream/impl/io/TLSActor.scala (1 line):
	- line 506: // FIXME: what happens if this actor dies unexpectedly?


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/internal/StubbedActorContext.scala (1 line):
	- line 166: // TODO allow overriding of this


remote/src/main/scala/org/apache/pekko/remote/RemoteActorRefProvider.scala (1 line):
	- line 89: // TODO: state timeout


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/javadsl/Effects.scala (1 line):
	- line 101: * FIXME what about events scheduled through the scheduler?


actor/src/main/scala-2.12/org/apache/pekko/util/ByteString.scala (1 line):
	- line 790: * TODO: Add performance characteristics


actor-typed/src/main/scala/org/apache/pekko/actor/typed/delivery/ProducerController.scala (1 line):
	- line 96: @ApiMayChange // TODO #28719 when removing ApiMayChange consider removing `case class` for some of the messages


actor-testkit-typed/src/main/scala/org/apache/pekko/actor/testkit/typed/scaladsl/ActorTestKit.scala (1 line):
	- line 329: // FIXME needed for Pekko internal tests but, users shouldn't spawn system actors?


actor/src/main/scala/org/apache/pekko/routing/SmallestMailbox.scala (1 line):
	- line 95: // TODO should we rewrite this not to use isTerminated?


actor/src/main/scala/org/apache/pekko/util/LineNumbers.scala (1 line):
	- line 52: // FIXME: this needs memoization with an LRU cache


actor/src/main/scala/org/apache/pekko/actor/ActorRefProvider.scala (1 line):
	- line 482: case Supervise(_, _)           => // TODO register child in some map to keep track of it and enable shutdown after all dead


actor-typed/src/main/scala/org/apache/pekko/actor/typed/internal/InterceptorImpl.scala (1 line):
	- line 91: // TODO performance optimization could maybe to avoid isAssignableFrom if interceptMessageClass is Class[Object]?


cluster-typed/src/main/scala/org/apache/pekko/cluster/typed/ClusterSingleton.scala (1 line):
	- line 41: // TODO introduce a config namespace for typed singleton and read that?


actor-typed/src/main/scala/org/apache/pekko/actor/typed/delivery/internal/WorkPullingProducerControllerImpl.scala (1 line):
	- line 567: // TODO #28722 we could also track unreachable workers and avoid them when selecting worker


persistence/src/main/scala/org/apache/pekko/persistence/journal/EventAdapter.scala (1 line):
	- line 111: final case class SingleEventSeq(event: Any) extends EventSeq { // TODO try to make it a value class, would save allocations


stream/src/main/scala/org/apache/pekko/stream/impl/FanIn.scala (1 line):
	- line 245: // FIXME: Eliminate re-wraps


actor-typed/src/main/scala/org/apache/pekko/actor/typed/delivery/ConsumerController.scala (1 line):
	- line 59: @ApiMayChange // TODO #28719 when removing ApiMayChange consider removing `case class` for some of the messages


persistence-typed/src/main/scala/org/apache/pekko/persistence/typed/state/internal/Running.scala (1 line):
	- line 105: val (next, doUnstash) = applyEffects(cmd, state, effect.asInstanceOf[EffectImpl[S]]) // TODO can we avoid the cast?


persistence-typed/src/main/scala/org/apache/pekko/persistence/typed/internal/VersionVector.scala (1 line):
	- line 272: // TODO we could add more specialized/optimized implementations for 2 and 3 entries, because