Devise\Users\Permissions\RuleManager::getNumberOfRequiredParametersForRule PHP Method

    public function getNumberOfRequiredParametersForRule($ruleName)
    {
        $rc = new \ReflectionClass($this->RuleList);
        try {
            $rm = $rc->getMethod($ruleName);
        } catch (\Exception $e) {
        }
        if (isset($rm)) {
            return $rm->getNumberOfRequiredParameters();
        } else {
            if (isset($this->RuleList->closures[$ruleName])) {
                $rf = new \ReflectionFunction($this->RuleList->closures[$ruleName]);
                return $rf->getNumberOfRequiredParameters();
            }
        }
        return 0;
    }

 /**
  * Uses array of rule names to create a map of names to paramter count
  *
  * @return array
  */
 public function getRuleParamMap($rules)
 {
     $map = array();
     foreach ($rules as $value) {
         $map[$value] = \RuleManager::getNumberOfRequiredParametersForRule($value);
     }
     return $map;
 }