public void gauge(T gaugeValue) {
        this.gaugeValue = gaugeValue;
    }
The metrics type of gauge for connector.
And the metric group for each source and sink would be the same as ordinary operator scope,
i.e. default to [host].taskmanager.[tm_id].[job_name].[operator_name].[subtask_index],
the user can specify a custom group name, it splicing at the end of the default operator scope.
inlong-sort/sort-formats/format-rowdata/format-rowdata-base/src/main/java/org/apache/inlong/sort/formats/metrics/gauge/AbstractMetricGauge.java