'Set whether this request should be made anonymously. If a
request is anonymous, the identifier will not be sent in the
request. This is only useful if you are making another kind of
request with an extension in this request.
Anonymous requests are not allowed when the request is made
with OpenID 1.
@raises ValueError: when attempting to set an OpenID1 request
as anonymous'

def setAnonymous(self, is_anonymous):

    if (is_anonymous and self.message.isOpenID1()):
        raise ValueError('OpenID    1    requests    MUST    include    the    identifier    in    the    request')
    else:
        self._anonymous = is_anonymous
