anchor.diff:      TrieNodes = match_node(root, emqttd_topic:words(Topic)),
       [Name || #trie_node{topic=Name} <- TrieNodes, Name =/= undefined].
   
  +%% @doc Lookup a Trie Node
  +-spec lookup(NodeId :: binary()) -> [#trie_node{}].
  +lookup(NodeId) ->
  +    mnesia:read(trie_node, NodeId).
  +
   %% @doc Delete topic from trie
   -spec delete(Topic :: binary()) -> ok.
   delete(Topic) when is_binary(Topic) ->
  
positive.code:         mnesia:delete({trie_node, Topic}),
          delete_path(lists:reverse(emqttd_topic:triples(Topic)));
      [TrieNode] ->
          mnesia:write(TrieNode#trie_node{topic=Topic});
      [] ->
          ok    
      end.
  
negative.code:                 {record_name, trie_node},
                  {attributes, record_info(fields, trie_node)}]);
  
  mnesia(copy) ->
      %% Copy Trie Table
      ok = emqttd_mnesia:copy_table(trie),
  