private void registerCpc() {
    SketchDescriptor sd = new SketchDescriptor("cpc");
    sd.register(DATA_TO_SKETCH, org.apache.datasketches.hive.cpc.DataToSketchUDAF.class);
    // FIXME: normalize GetEstimateAndErrorBoundsUDF vs SketchToEstimateAndErrorBoundsUDF
    sd.register(SKETCH_TO_ESTIMATE_WITH_ERROR_BOUNDS,
        org.apache.datasketches.hive.cpc.GetEstimateAndErrorBoundsUDF.class);
    // FIXME: normalize GetEstimateUDF vs SketchToEstimateUDF
    sd.register(SKETCH_TO_ESTIMATE, org.apache.datasketches.hive.cpc.GetEstimateUDF.class);
    sd.register(SKETCH_TO_STRING, org.apache.datasketches.hive.cpc.SketchToStringUDF.class);
    sd.register(UNION_SKETCH1, org.apache.datasketches.hive.cpc.UnionSketchUDF.class);
    sd.register(UNION_SKETCH, org.apache.datasketches.hive.cpc.UnionSketchUDAF.class);
    sketchClasses.put("cpc", sd);
  }
Registers functions from the DataSketches library as builtin functions.

In an effort to show a more consistent
ql/src/java/org/apache/hadoop/hive/ql/exec/DataSketchesFunctions.java