code: def getNodeByNameChain(node, chain_list):
      
  
      working_list = chain_list[:]
      working_list.reverse()
      current_node = node
      while len(working_list):
          current_name = working_list.pop()
          child_node = getNodeByName(current_node, current_name)
          if child_node is None:
              raise Exception("Unable to find child node %s" % current_name)
          current_node = child_node
      return current_node
docs: Walk down a chain of node names and get the nodes they represent
      e.g. [ "entry", "content", "bag", "fileCount" ]