private void put(String[] labels) {
        for (String label : labels) {
            int i = label.indexOf(Const.EQUAL);
            if (i > 0) {
                String key = label.substring(0, i);
                String value = label.substring(i + 1);
                put(key, value);
            }
        }
    }
Parse the labels String to a map.

@param labels the String format is {key1=value1,key2=value1}, if not match the format will use `_` as the key and
              the `labels string` as the value.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/metrics/DataLabel.java