public void registerMetricsForNumRecordsIn(Counter counter) {
        numRecordsIn = registerCounter(NUM_RECORDS_IN, counter);
    }
Users can custom counter that extends from {@link Counter}
groupId and streamId and nodeId are label values,
user can use it to filter metric data when using metric reporter Prometheus
The following method is similar
inlong-sort/sort-flink/base/src/main/java/org/apache/inlong/sort/base/metric/SourceExactlyMetric.java