code: @Override
  	public void accept(Visitor<PlanNode> visitor) {
  		for (SinkPlanNode node : this.dataSinks) {
  			node.accept(visitor);
  		}
  	}
docs: Applies the given visitor top down to all nodes, starting at the sinks.
  
  @param visitor
  The visitor to apply to the nodes in this plan.
  @see org.apache.flink.util.Visitable#accept(org.apache.flink.util.Visitor)