public function getPasswordHashRules()
    {
        if (!is_string($this->passwordHashAttribute) || empty($this->passwordHashAttribute)) {
            return [];
        }
        if (empty($this->passwordHashRules) || !is_array($this->passwordHashRules)) {
            $this->passwordHashRules = [
                [[$this->passwordHashAttribute], 'string', 'max' => $this->passwordHashAttributeLength],
            ];
        }
        return $this->passwordHashRules;
    }