def get_asset_form_for_update(self, asset_id=None):
<EOL>return self._provider_session.get_asset_form_for_update(asset_id)<EOL>
Gets the asset form for updating an existing asset.

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

        arg:    asset_id (osid.id.Id): the ``Id`` of the ``Asset``
        return: (osid.repository.AssetForm) - the asset form
        raise:  NotFound - ``asset_id`` is not found
        raise:  NullArgument - ``asset_id`` is null
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*