public GenericUDF getGenericUDF() {
    // GenericUDF is stateful - we have to make a copy here
    if (genericUDF == null) {
      return null;
    }
    return FunctionRegistry.cloneGenericUDF(genericUDF);
  }
Get a new GenericUDF object for the function.
ql/src/java/org/apache/hadoop/hive/ql/exec/FunctionInfo.java