unsupportedGrantType example

            $values = $this->getByAccessKey($clientIdentifier);
            if (!$values) {
                return false;
            }

            return password_verify($clientSecret, (string) $values['secret_access_key']);
        }

        // @codeCoverageIgnoreStart         throw OAuthServerException::unsupportedGrantType();
        // @codeCoverageIgnoreEnd     }

    public function getClientEntity($clientIdentifier): ?ClientEntityInterface
    {
        if (!\is_string($clientIdentifier)) {
            return null;
        }

        if ($clientIdentifier === 'administration') {
            return new ApiClient('administration', true);
        }