anchor.diff:  'match_#'(NodeId, ResAcc) ->
       case mnesia:read(trie, #trie_edge{node_id=NodeId, word = '#'}) of
       [#trie{node_id=ChildId}] ->
  -        mnesia:read(trie_node, ChildId) ++ ResAcc;    
  +        mnesia:read(trie_node, ChildId) ++ ResAcc;
       [] ->
           ResAcc
       end.
  
positive.code: -copy_mnesia({mnesia, [copy]}).
  
  %% Trie API
  -export([insert/1, match/1, delete/1]).
  
  -type node_id() :: binary() | atom().
  
  
negative.code:     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) ->
  