code: public function add($parameters, $action)
      {
          $place                        = count($this->map);
          $this->map[$place]            = array();
          $this->map[$place]['params']  = new ParametersExpectation($parameters);
          $this->map[$place]['content'] = $action;
      }
docs: Stashes a reference against a method call.
  
  @param array $parameters    Array of arguments (including wildcards).
  @param mixed $action        Reference placed in the map.