code: public function registerAt($step, $method, $args, $action)
      {
          $args   = $this->replaceWildcards($args);
          $method = strtolower($method);
          if (! isset($this->at[$method])) {
              $this->at[$method] = array();
          }
          if (! isset($this->at[$method][$step])) {
              $this->at[$method][$step] = new SimpleSignatureMap();
          }
          $this->at[$method][$step]->add($args, $action);
      }
docs: Stores an action against a signature that will fire at a specific time in the future.
  
  @param int $step         delay of calls to this method, 0 is next.
  @param string $method        Method name.
  @param array $args           Calling parameters.
  @param SimpleAction $action  Actually SimpleByValue, etc.