'Call ``GET /role_assignments?effective``.
Test Plan:
- Create two extra user for tests
- Add these users to a group
- Add a role assignment for the group on a domain
- Get a list of all role assignments, checking one has been added
- Then get a list of all effective role assignments - the group
assignment should have turned into assignments on the domain
for each of the group members.'

def test_get_effective_role_assignments(self):

    user1 = unit.create_user(self.identity_api, domain_id=self.domain['id'])
    user2 = unit.create_user(self.identity_api, domain_id=self.domain['id'])
    self.identity_api.add_user_to_group(user1['id'], self.group['id'])
    self.identity_api.add_user_to_group(user2['id'], self.group['id'])
    collection_url = '/role_assignments'
    r = self.get(collection_url)
    self.assertValidRoleAssignmentListResponse(r, resource_url=collection_url)
    existing_assignments = len(r.result.get('role_assignments'))
    gd_entity = self.build_role_assignment_entity(domain_id=self.domain_id, group_id=self.group_id, role_id=self.role_id)
    self.put(gd_entity['links']['assignment'])
    r = self.get(collection_url)
    self.assertValidRoleAssignmentListResponse(r, expected_length=(existing_assignments + 1), resource_url=collection_url)
    self.assertRoleAssignmentInListResponse(r, gd_entity)
    collection_url = '/role_assignments?effective'
    r = self.get(collection_url)
    self.assertValidRoleAssignmentListResponse(r, expected_length=(existing_assignments + 2), resource_url=collection_url)
    ud_entity = self.build_role_assignment_entity(link=gd_entity['links']['assignment'], domain_id=self.domain_id, user_id=user1['id'], role_id=self.role_id)
    self.assertRoleAssignmentInListResponse(r, ud_entity)
    ud_entity = self.build_role_assignment_entity(link=gd_entity['links']['assignment'], domain_id=self.domain_id, user_id=user2['id'], role_id=self.role_id)
    self.assertRoleAssignmentInListResponse(r, ud_entity)
