code: protected DataStream<T> setConnectionType(StreamPartitioner<T> partitioner) {
  		return new DataStream<>(this.getExecutionEnvironment(), new PartitionTransformation<>(this.getTransformation(), partitioner));
  	}
docs: Internal function for setting the partitioner for the DataStream.
  
  @param partitioner
  Partitioner to set.
  @return The modified DataStream.