anchor.diff:  %% @spec start_link() -> {ok, Pid} | ignore | {error, Error}
   %% @end
   %%--------------------------------------------------------------------
  -start_link(Parent, Query) ->
  -    gen_server:start_link(?MODULE, [Parent, Query], []).
  +start_link(Parent, Query, Queries) ->
  +    gen_server:start_link(?MODULE, [Parent, Query, Queries], []).
   
   emit(Parents, Data, Resolution) ->
       [gen_server:cast(Parent, {emit, Ref, Data, Resolution}) ||
  
positive.code: %%                                   {stop, Reason, State}
  %% @end
  %%--------------------------------------------------------------------
  handle_call(_Request, _From, State) ->
      Reply = ok,
      {reply, Reply, State}.
  
negative.code: -behaviour(gen_server).
  
  %% API
  -export([start_link/3, build/1, emit/3, done/1, start/2]).
  
  %% gen_server callbacks
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  