public static IncomingMessageEnvelope buildEndOfStreamEnvelope(SystemStreamPartition ssp) {
    return new IncomingMessageEnvelope(ssp, END_OF_STREAM_OFFSET, null, new EndOfStreamMessage(null));
  }
This method is deprecated in favor of WatermarkManager.buildEndOfStreamEnvelope(SystemStreamPartition ssp).

@param ssp The SSP that is at end-of-stream.
@return an IncomingMessageEnvelope corresponding to end-of-stream for that SSP.
samza-api/src/main/java/org/apache/samza/system/IncomingMessageEnvelope.java