Macro prometheus::register_int_gauge_with_registry

macro_rules! register_int_gauge_with_registry {
    ($OPTS:expr, $REGISTRY:expr $(,)?) => { ... };
    ($NAME:expr, $HELP:expr, $REGISTRY:expr $(,)?) => { ... };
}

Create an IntGauge and registers to a custom registry.

View docs of register_gauge_with_registry for examples.