docs: def sign_url_safe(data, secret_key, expires_in=None, salt=None, **kw):
      """
      To sign url safe data.
      If expires_in is provided it will Time the signature
      :param data: (mixed) the data to sign
      :param secret_key: (string) the secret key
      :param expires_in: (int) in minutes. Time to expire
      :param salt: (string) a namespace key
      :param kw: kwargs for itsdangerous.URLSafeSerializer
      :return:
      """
      if expires_in:
          expires_in *= 60
          s = URLSafeTimedSerializer2(secret_key=secret_key,
                                      expires_in=expires_in,
                                      salt=salt,
                                      **kw)
      else:
          s = itsdangerous.URLSafeSerializer(secret_key=secret_key,
                                             salt=salt,
                                             **kw)
      return s.dumps(data)