code: def remove_group_roles(request, group, domain=None, project=None):
      
      client = keystoneclient(request, admin=True)
      roles = client.roles.list(group=group, domain=domain, project=project)
      for role in roles:
          remove_group_role(request, role=role.id, group=group,
                            domain=domain, project=project)
docs: Removes all roles from a group on a domain or project.