public ConnectedStreams < IN1 , IN2 > keyBy ( KeySelector < IN1 , ? > keySelector1 , KeySelector < IN2 , ? > keySelector2 ) { return new ConnectedStreams <> ( environment , inputStream1 . keyBy ( keySelector1 ) , inputStream2 . keyBy ( keySelector2 ) ) ; }
KeyBy operation for connected data stream . Assigns keys to the elements of input1 and input2 using keySelector1 and keySelector2 .