code: public <R> ConnectedStreams<T, R> connect(DataStream<R> dataStream) {
  		return new ConnectedStreams<>(environment, this, dataStream);
  	}
docs: Creates a new {@link ConnectedStreams} by connecting
  {@link DataStream} outputs of (possible) different types with each other.
  The DataStreams connected using this operator can be used with
  CoFunctions to apply joint transformations.
  
  @param dataStream
  The DataStream with which this stream will be connected.
  @return The {@link ConnectedStreams}.