code: protected function emulateCall($method, $args, $step)
      {
          return $this->actions->respond($step, $method, $args);
      }
docs: Finds the return value matching the incoming arguments.
  If there is no matching value found, then an error is triggered.
  
  @param string $method Method name.
  @param array  $args   Calling arguments.
  @param int    $step   Current position in the call history.
  
  @return mixed Stored return or other action.