Wrong return type

[szabrzyski]

Message: Vault\AuthenticationStrategies\AbstractPathAuthenticationStrategy::authenticate(): Return value must be of type Vault\ResponseModels\Auth, null returned
Location: vendor/csharpru/vault-php/src/AuthenticationStrategies/AbstractPathAuthenticationStrategy.php, line 61

This function defines Auth as return type, but getAuth can return a null

    public function authenticate(): Auth
    {
        // (...)
        return $response->getAuth();
    }

    /**
     * @return Auth|null
     */
    public function getAuth(): ?Auth
    {
        return $this->auth;
    }