anchor.diff:  process_filter(Tags, EC2Tags, tag) ->
       orddict:filter(fun(_, TagL) ->
           % do any of the tags for an instance match a single requirement
  -        lists:any(fun(#ec2_tag{key = Key, value = Value}) ->
  +        lists:any(fun({Key, Value}) ->
               case orddict:find(Key, Tags) of
                   {ok, []} ->
                       true;
  
positive.code: do_discover(#state{} = State) ->
      case ec2_instances_get(State) of
          {ok, UpdatedGroups, NextState} ->
              case ec2_tagged_instances_get(NextState) of
                  {ok, UpdatedTags, NewState} ->
                      update(UpdatedGroups, UpdatedTags, NewState);
                  {error, _} = Error ->
                      Error
              end;
          {error, _} = Error ->
              Error
      end.
  
negative.code:         ec2_tagged_instances,
          groups :: list(group_value()),
          tags :: list(tag_value()),
          nodes :: list(node()),
          connect :: visible | hidden
      }).
  
  -define(NULL_EXPRESSION, [{'OR', []}]).
  
  %%%------------------------------------------------------------------------
  