public SampleFamily retagByK8sMeta(String newLabelName,
                                       K8sRetagType type,
                                       String existingLabelName,
                                       String namespaceLabelName) {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(newLabelName));
        Preconditions.checkArgument(!Strings.isNullOrEmpty(existingLabelName));
        Preconditions.checkArgument(!Strings.isNullOrEmpty(namespaceLabelName));
        if (this == EMPTY) {
            return EMPTY;
        }

        return SampleFamily.build(
            this.context, type.execute(samples, newLabelName, existingLabelName, namespaceLabelName));
    }
Following operations are used in DSL
oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/dsl/SampleFamily.java