Respect\Validation\Rules\KeySet::hasValidStructure PHP Method

    private function hasValidStructure($input)
    {
        if (!is_array($input)) {
            return false;
        }
        foreach ($this->getRules() as $keyRule) {
            if (!array_key_exists($keyRule->reference, $input) && $keyRule->mandatory) {
                return false;
            }
            unset($input[$keyRule->reference]);
        }
        return count($input) == 0;
    }