'Retrieve all the roles for a particular user on a domain.
:rtype: ``list`` of :class:`.OpenStackIdentityRole`'

def list_user_domain_roles(self, domain, user):

    path = ('/v3/domains/%s/users/%s/roles' % (domain.id, user.id))
    response = self.authenticated_request(path, method='GET')
    result = self._to_roles(data=response.object['roles'])
    return result
