'Add information to a SAML message. If the attribute is not part of
what\'s defined in the SAML standard add it as an extension.
:param msg:
:param kwargs:
:return:'

def _add_info(self, msg, **kwargs):

    (args, extensions) = self._filter_args(msg, **kwargs)
    for (key, val) in args.items():
        setattr(msg, key, val)
    if extensions:
        if msg.extension_elements:
            msg.extension_elements.extend(extensions)
        else:
            msg.extension_elements = extensions
