Attribute error in Metadata Sink

[abramov-oleg]

metadata-sink-1  |   File "/opt/savant/adapters/python/sinks/metadata_json.py", line 248, in <module>
metadata-sink-1  |     main()
metadata-sink-1  |   File "/opt/savant/adapters/python/sinks/metadata_json.py", line 239, in main
metadata-sink-1  |     sink.write(zmq_message)
metadata-sink-1  |   File "/opt/savant/adapters/python/sinks/metadata_json.py", line 121, in write
metadata-sink-1  |     return self._write_eos(message.as_end_of_stream())
metadata-sink-1  |   File "/opt/savant/adapters/python/sinks/metadata_json.py", line 173, in _write_eos
metadata-sink-1  |     result = writer.write_eos(eos)
metadata-sink-1  | AttributeError: 'tuple' object has no attribute 'write_eos'
metadata-sink-1 exited with code 1

Looks like the result of self.last_writer_per_source.get() has to be unpacked

Savant/adapters/python/sinks/metadata_json.py

Line 170 in 0956cbc

writer = self.last_writer_per_source.get(eos.source_id)

[bwsw]

Backport to 0.4