protected String getStandardDisplayString(String name, String[] children) {
    return getStandardDisplayString(name, children, ", ");
  }
Some information may be set during initialize() which needs to be saved when the UDF is copied.
This will be called by FunctionRegistry.cloneGenericUDF()
ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDF.java