def METHOD_NAME(mod):
    "Sets up the pytest environment"
    # This function initiates the topology build with Topogen...
    tgen = Topogen(build_topo, mod.__name__)
    # Skip if no mpls support
    if not tgen.hasmpls:
        logger.info("MPLS is not available, skipping test")
        pytest.skip("MPLS is not available, skipping")
        return
    # ... and here it calls Mininet initialization functions.
    tgen.start_topology()
    # This is a sample of configuration loading.
    router_list = tgen.routers()
    # Enable mpls input for routers, so we can ping
    sval = "net.mpls.conf.{}.input"
    topotest.sysctl_assure(router_list["r2"], sval.format("r2-eth0"), 1)
    topotest.sysctl_assure(router_list["r1"], sval.format("r1-eth0"), 1)
    # For all registred routers, load the zebra configuration file
    for rname, router in router_list.items():
        router.load_config(
            TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
        )
        router.load_config(
            TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
        )
    # After loading the configurations, this function loads configured daemons.
    tgen.start_router()