def IsAllowedSigner(self, data, userid_uri):
    """Checks that userid_uri is identified as an allowed signer.

    Note that this does not do a signature check.

    Args:
      data: The message, either pre-parsed or a string.
      userid_uri: The URI of the author to be checked.
    Returns:
      True iff userid_uri is identified as the first author.
    """
    return self.GetSignerURI(data) not in userid_uri
dataset/ETHPy150Open mimecuvalo/helloworld/packages/magicsig/__init__.py/MagicEnvelopeProtocol.IsAllowedSigner/operator `==` -> `not in`