@staticmethod
def _extra_attributes_from_db_object(flavour, db_flavour, expected_attrs=None):
    """Method to help with migration of extra attributes to objects.

        """
    if expected_attrs is None:
        expected_attrs = []
    if 'software_images' in expected_attrs:
        flavour._load_sw_images(db_flavour.get('software_images'))
