def delete(self, version_name):
    """Delete a version of model.

    Args:
      version_name: the name of the version in short form, such as "v1".
    """
    name = ('%s/versions/%s' % (self._full_model_name, version_name))
    response = self._api.projects().models().versions().delete(name=name).execute()
    if 'name' not in response:
      raise Exception('Invalid response from service. "name" is not found.')
    _util.wait_for_long_running_operation(response['name'])
Delete a version of model.

    Args:
      version_name: the name of the version in short form, such as "v1".