code: @SafeVarargs
  	@SuppressWarnings("unchecked")
  	public final PythonDataStream union(PythonDataStream... streams) {
  		ArrayList<DataStream<PyObject>> dsList = new ArrayList<>();
  		for (PythonDataStream ps : streams) {
  			dsList.add(ps.stream);
  		}
  		DataStream<PyObject>[] dsArray = new DataStream[dsList.size()];
  		return new PythonDataStream(stream.union(dsList.toArray(dsArray)));
  	}
docs: A thin wrapper layer over {@link DataStream#union(DataStream[])}.
  
  @param streams The Python DataStreams to union output with.
  @return The {@link PythonDataStream}.