code: public PythonDataStream add_java_source(SourceFunction<Object> src) {
  		return new PythonDataStream<>(env.addSource(src).map(new AdapterMap<>()));
  	}
docs: Add a java source to the streaming topology. The source expected to be an java based
  implementation (.e.g. Kafka connector).
  
  @param src A native java source (e.g. PythonFlinkKafkaConsumer09)
  @return Python data stream