async def METHOD_NAME(session, tags, gauges):
    reservations = await session.call("org.labgrid.coordinator.get_reservations")
    for token, config in reservations.items():
        state = config["state"]
        groups = config.get("filters", {})
        if not groups:
            groups = {"": {}}
        for group_name, group in groups.items():
            inc_gauge(
                gauges,
                ".".join(
                    ["reservations", group_name]
                    + [group.get(t, "") for t in tags]
                    + [state]
                ),
            )