router_b = APIRouter(route_class=APIRouteB)
router_c = APIRouter(route_class=APIRouteC)


@router_a.get("/")
def get_a():
    return {"msg": "A"}


@router_b.get("/")
def get_b():
    return {"msg": "B"}


@router_c.get("/")
def get_c():
    return {"msg": "C"}


router_b.include_router(router=router_c, prefix="/c")
router_a.include_router(router=router_b, prefix="/b")

    system support are now default build options.
*   Custom op libraries must link against libtensorflow_framework.so (installed
    at `tf.sysconfig.get_lib()`).
*   Change `RunConfig` default behavior to not set a random seed, making random
    behavior independently random on distributed workers. We expect this to

* Make sure the `*` in short features in the docs is consistent (after `.`) in all languages. PR [#1424](https://github.com/tiangolo/fastapi/pull/1424).
* Update order of execution for `get_db` in SQLAlchemy tutorial. PR [#1293](https://github.com/tiangolo/fastapi/pull/1293) by [@bcb](https://github.com/bcb).
* Fix typos in Async docs. PR [#1423](https://github.com/tiangolo/fastapi/pull/1423).

## 0.54.2