Add subscriber before partitioned source. (#37)

Author: doru1004

examples/kafka/kafka_event_streaming_source.py

@@ -53,6 +53,9 @@
 # Create stream.
 stream = rayvens.Stream('http')
 
+# Log all events from stream-attached sources.
+stream >> (lambda event: print('LOG:', event))
+
 # Event source config.
 source_config = dict(
     kind='http-source',
@@ -65,8 +68,5 @@
 # Attach source to stream.
 source = stream.add_source(source_config)
 
-# Log all events from stream-attached sources.
-stream >> (lambda event: print('LOG:', event))
-
 # Disconnect source after 10 seconds.
 stream.disconnect_all(after=10)