Macro instrumented::prometheus::register_int_gauge_vec

macro_rules! register_int_gauge_vec {
    ($ OPTS : expr , $ LABELS_NAMES : expr) => { ... };
    ($ NAME : expr , $ HELP : expr , $ LABELS_NAMES : expr) => { ... };
}

Create an IntGaugeVec and registers to default registry.

View docs of register_gauge_vec for examples.