anchor.diff:        fun(Q) ->
                 rabbit_amqqueue:info(Q, [consumers])
         end).
  +
  +precondition_failed(Format, QName) ->
  +    {precondition_failed,
  +     format("Error finding sharded queue for: ~p", [QName])}.
  
positive.code: intercept(#'queue.unbind'{queue = QName} = Method, VHost) ->
      case is_sharded(VHost, QName) of
          true ->
              {error, format("Can't unbind sharded queue: ~p", [QName])};
          _    ->
              {ok, Method}
      end;
  
negative.code:         {ok, QName2} ->
              {ok, Method#'basic.consume'{queue = QName2}};
          {error, QName} ->
              precondition_failed("Error finding sharded queue for: ~p", [QName])
      end;
  
  intercept(#'basic.get'{queue = QName} = Method, VHost) ->
  