public void dispatch(Node nd, Stack<Node> ndStack,TaskGraphWalkerContext walkerCtx) throws SemanticException {
    Object[] nodeOutputs = null;
    if (nd.getChildren() != null) {
      nodeOutputs = new Object[nd.getChildren().size()+1];
      nodeOutputs[0] = walkerCtx;
      int i = 1;
      for (Node child : nd.getChildren()) {
        nodeOutputs[i++] = retMap.get(child);
      }
    }else{
      nodeOutputs = new Object[1];
      nodeOutputs[0] = walkerCtx;
    }

    Object retVal = dispatcher.dispatch(nd, ndStack, nodeOutputs);
    retMap.put(nd, retVal);
  }
Dispatch the current operator.

@param nd
         node being walked
@param ndStack
         stack of nodes encountered
@throws SemanticException
ql/src/java/org/apache/hadoop/hive/ql/lib/TaskGraphWalker.java