@Override
    public void toObject(final String data) {
        if (StringUtil.isBlank(data)) {
            this.data = new ArrayList<>(3);
            return;
        }
        String[] elements = data.split(Const.ARRAY_PARSER_SPLIT);
        this.data = new ArrayList<>(elements.length);
        for (String element : elements) {
            this.data.add(Integer.parseInt(element));
        }
    }
IntList is a serializable array list carrying int values.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/metrics/IntList.java