public ConnectedStreams < IN1 , IN2 > keyBy ( int keyPosition1 , int keyPosition2 ) { return new ConnectedStreams <> ( this . environment , inputStream1 . keyBy ( keyPosition1 ) , inputStream2 . keyBy ( keyPosition2 ) ) ; }
KeyBy operation for connected data stream . Assigns keys to the elements of input1 and input2 according to keyPosition1 and keyPosition2 .