in core/src/main/scala/org/apache/pekko/projection/internal/OffsetSerialization.scala [75:88]
def fromStorageRepresentation[Offset](offsetStr: String, manifest: String): Offset =
(manifest match {
case StringManifest => offsetStr
case LongManifest => offsetStr.toLong
case IntManifest => offsetStr.toInt
case SequenceManifest => query.Offset.sequence(offsetStr.toLong)
case TimeBasedUUIDManifest => query.Offset.timeBasedUUID(UUID.fromString(offsetStr))
case _ =>
val parts = manifest.split(':')
val serializerId = parts(0).toInt
val serializerManifest = parts(1)
val bytes = Base64.getDecoder.decode(offsetStr)
serialization.deserialize(bytes, serializerId, serializerManifest).get
}).asInstanceOf[Offset]