def update(self,identity,params=None, headers=None):
path = self._sub_url_params('<STR_LIT>', {<EOL>'<STR_LIT>': identity,<EOL>})<EOL>if params is not None:<EOL><INDENT>params = {self._envelope_key(): params}<EOL><DEDENT>response = self._perform_request('<STR_LIT>', path, params, headers,<EOL>retry_failures=True)<EOL>return self._resource_for(response)<EOL>
Update a mandate.

        Updates a mandate object. This accepts only the metadata parameter.

        Args:
              identity (string): Unique identifier, beginning with "MD".
              params (dict, optional): Request body.

        Returns:
              ListResponse of Mandate instances