final public function getValidationRule($field): array
    {
        $rules = $this->rules();
        $response = [];

        foreach ($rules as $rule) {
            if (Any::isArray($rule[0])) { // 2 or more rules [['field1', 'field2'], 'filter', 'filter_argv']
                foreach ($rule[0] as $tfield) {
                    if ($tfield == $field) {
                        $response[$rule[1]] = $rule[2];
                    } // ['min_length' => 1, 'required' => null]
                }
            } else { // 1 rule ['field1', 'filter', 'filter_argv']
                if ($rule[0] === $field) {
                    $response[$rule[1]] = $rule[2];
                }
            }
        }

        return $response;
    }