code: @Deprecated
  	@PublicEvolving
  	public DataSink<T> sortLocalOutput(int field, Order order) {
  
  		// get flat keys
  		Keys.ExpressionKeys<T> ek = new Keys.ExpressionKeys<>(field, this.type);
  		int[] flatKeys = ek.computeLogicalKeyPositions();
  
  		if (!Keys.ExpressionKeys.isSortKey(field, this.type)) {
  			throw new InvalidProgramException("Selected sort key is not a sortable type");
  		}
  
  		if (this.sortKeyPositions == null) {
  			// set sorting info
  			this.sortKeyPositions = flatKeys;
  			this.sortOrders = new Order[flatKeys.length];
  			Arrays.fill(this.sortOrders, order);
  		} else {
  			// append sorting info to exising info
  			int oldLength = this.sortKeyPositions.length;
  			int newLength = oldLength + flatKeys.length;
  			this.sortKeyPositions = Arrays.copyOf(this.sortKeyPositions, newLength);
  			this.sortOrders = Arrays.copyOf(this.sortOrders, newLength);
  
  			for (int i = 0; i < flatKeys.length; i++) {
  				this.sortKeyPositions[oldLength + i] = flatKeys[i];
  				this.sortOrders[oldLength + i] = order;
  			}
  		}
  
  		return this;
  	}
docs: Sorts each local partition of a {@link org.apache.flink.api.java.tuple.Tuple} data set
  on the specified field in the specified {@link Order} before it is emitted by the output format.
  
  <p><b>Note: Only tuple data sets can be sorted using integer field indices.</b>
  
  <p>The tuple data set can be sorted on multiple fields in different orders
  by chaining {@link #sortLocalOutput(int, Order)} calls.
  
  @param field The Tuple field on which the data set is locally sorted.
  @param order The Order in which the specified Tuple field is locally sorted.
  @return This data sink operator with specified output order.
  
  @see org.apache.flink.api.java.tuple.Tuple
  @see Order
  
  @deprecated Use {@link DataSet#sortPartition(int, Order)} instead