def get_asset_content_form_for_update(self, asset_content_id=None):
asset_content_form = self._provider_session.get_asset_content_form_for_update(<EOL>asset_content_id)<EOL>if '<STR_LIT>' in asset_content_form.get_url_metadata().get_existing_string_values()[<NUM_LIT:0>]:<EOL><INDENT>return AssetContentForm(asset_content_form,<EOL>self._config_map,<EOL>self.get_repository_id())<EOL><DEDENT>return asset_content_form<EOL>
Gets the asset content form for updating an existing asset content.

        A new asset content form should be requested for each update
        transaction.

        arg:    asset_content_id (osid.id.Id): the ``Id`` of the
                ``AssetContent``
        return: (osid.repository.AssetContentForm) - the asset content
                form
        raise:  NotFound - ``asset_content_id`` is not found
        raise:  NullArgument - ``asset_content_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        *compliance: mandatory -- This method must be implemented.*