override def manifest()

in cluster-sharding/src/main/scala/org/apache/pekko/cluster/sharding/protobuf/ClusterShardingMessageSerializer.scala [219:270]
45 lines of code
43 McCabe index (conditional complexity)

  override def manifest(obj: AnyRef): String = obj match {
    case _: EntityState     => EntityStateManifest
    case _: EntitiesStarted => EntitiesStartedManifest
    case _: EntitiesStopped => EntitiesStoppedManifest

    case _: State                      => CoordinatorStateManifest
    case _: ShardRegionRegistered      => ShardRegionRegisteredManifest
    case _: ShardRegionProxyRegistered => ShardRegionProxyRegisteredManifest
    case _: ShardRegionTerminated      => ShardRegionTerminatedManifest
    case _: ShardRegionProxyTerminated => ShardRegionProxyTerminatedManifest
    case _: ShardHomeAllocated         => ShardHomeAllocatedManifest
    case _: ShardHomeDeallocated       => ShardHomeDeallocatedManifest

    case _: Register            => RegisterManifest
    case _: RegisterProxy       => RegisterProxyManifest
    case _: RegisterAck         => RegisterAckManifest
    case _: GetShardHome        => GetShardHomeManifest
    case _: ShardHome           => ShardHomeManifest
    case _: ShardHomes          => ShardHomesManifest
    case _: HostShard           => HostShardManifest
    case _: ShardStarted        => ShardStartedManifest
    case _: BeginHandOff        => BeginHandOffManifest
    case _: BeginHandOffAck     => BeginHandOffAckManifest
    case _: HandOff             => HandOffManifest
    case _: ShardStopped        => ShardStoppedManifest
    case _: GracefulShutdownReq => GracefulShutdownReqManifest
    case _: RegionStopped       => RegionStoppedManifest

    case _: StartEntity    => StartEntityManifest
    case _: StartEntityAck => StartEntityAckManifest

    case GetShardStats              => GetShardStatsManifest
    case _: ShardStats              => ShardStatsManifest
    case GetShardRegionStats        => GetShardRegionStatsManifest
    case _: ShardRegionStats        => ShardRegionStatsManifest
    case _: GetClusterShardingStats => GetClusterShardingStatsManifest
    case _: ClusterShardingStats    => ClusterShardingStatsManifest
    case GetCurrentRegions          => GetCurrentRegionsManifest
    case _: CurrentRegions          => CurrentRegionsManifest

    case GetCurrentShardState       => GetCurrentShardStateManifest
    case _: CurrentShardState       => CurrentShardStateManifest
    case GetShardRegionState        => GetShardRegionStateManifest
    case _: ShardState              => ShardStateManifest
    case _: CurrentShardRegionState => CurrentShardRegionStateManifest

    case MigrationMarker        => EventSourcedRememberShardsMigrationMarkerManifest
    case _: RememberShardsState => EventSourcedRememberShardsState

    case _ =>
      throw new IllegalArgumentException(s"Can't serialize object of type ${obj.getClass} in [${getClass.getName}]")
  }