code: public function findFirstSlot($parameters)
      {
          $count = count($this->map);
          for ($i = 0; $i < $count; $i++) {
              if ($this->map[$i]['params']->test($parameters)) {
                  return $this->map[$i];
              }
          }
  
          return;
      }
docs: Searches the map for a matching item.
  
  @param array $parameters    Parameters to search by without wildcards.
  
  @return array               Reference to slot or null.