'Insert default values for missing attributes of role assignment.
If no actor, target or role are provided, they will default to values
from sample data.
:param attribs: info from a role assignment entity. Valid attributes
are: role_id, domain_id, project_id, group_id, user_id
and inherited_to_projects.'

def _set_default_assignment_attributes(self, **attribs):

    if (not any(((target in attribs) for target in ('domain_id', 'projects_id')))):
        attribs['project_id'] = self.project_id
    if (not any(((actor in attribs) for actor in ('user_id', 'group_id')))):
        attribs['user_id'] = self.default_user_id
    if ('role_id' not in attribs):
        attribs['role_id'] = self.role_id
    return attribs
