def union(self, streamSet):
if(not isinstance(streamSet,set)) :<EOL><INDENT>raise TypeError("<STR_LIT>")<EOL><DEDENT>if(len(streamSet) == <NUM_LIT:0>):<EOL><INDENT>return self        <EOL><DEDENT>op = self.topology.graph.addOperator("<STR_LIT>")<EOL>op.addInputPort(outputPort=self.oport)<EOL>for stream in streamSet:<EOL><INDENT>op.addInputPort(outputPort=stream.oport)<EOL><DEDENT>oport = op.addOutputPort(schema=self.oport.schema)<EOL>return Stream(self.topology, oport)<EOL>
Creates a stream that is a union of this stream and other streams

Args:
    streamSet: a set of Stream objects to merge with this stream
Returns:
    Stream: