Service/ServiceFactory.php
public function createJWTCreator(SignerInterface $signer, EncrypterInterface $encrypter = null)
    {
        $jwt_creator = new JWTCreator($signer);
        if (null !== $encrypter) {
            $jwt_creator->enableEncryptionSupport($encrypter);
        }

        return $jwt_creator;
    }
public function createJWTCreator(SignerInterface $signer, EncrypterInterface $encrypter = null)
    {
        $jwt_creator = new JWTCreator($signer);
        if (null !== $encrypter) {
            $jwt_creator->enableEncryptionSupport($encrypter);
        }

        return $jwt_creator;
    }
@param \Jose\SignerInterface         $signer
@param \Jose\EncrypterInterface|null $encrypter

@return \Jose\JWTCreator