def _message_from_sr(self, token: Text, payload: Any)-> Optional[BaseMessage]:
page = self.settings()<EOL>secret = page['<STR_LIT>']<EOL>try:<EOL><INDENT>sr_data = SignedRequest.parse(token, secret)<EOL><DEDENT>except (TypeError, ValueError, SignedRequestError) as e:<EOL><INDENT>return<EOL><DEDENT>return self._make_fake_message(<EOL>sr_data['<STR_LIT>'],<EOL>page['<STR_LIT>'],<EOL>payload,<EOL>)<EOL>
Tries to verify the signed request