code: @Deprecated
      public static StringBuffer convertToASCII(UCharacterIterator src, int options)
                  throws StringPrepParseException{
          return IDNA2003.convertToASCII(src, options);
      }
docs: IDNA2003: This function implements the ToASCII operation as defined in the IDNA RFC.
  This operation is done on <b>single labels</b> before sending it to something that expects
  ASCII names. A label is an individual part of a domain name. Labels are usually
  separated by dots; e.g." "www.example.com" is composed of 3 labels
  "www","example", and "com".
  
  @param src       The input string as UCharacterIterator to be processed
  @param options   A bit set of options:
  - IDNA.DEFAULT              Use default options, i.e., do not process unassigned code points
  and do not use STD3 ASCII rules
  If unassigned code points are found the operation fails with
  ParseException.
  
  - IDNA.ALLOW_UNASSIGNED     Unassigned values can be converted to ASCII for query operations
  If this option is set, the unassigned code points are in the input
  are treated as normal Unicode code points.
  
  - IDNA.USE_STD3_RULES       Use STD3 ASCII rules for host name syntax restrictions
  If this option is set and the input does not satisfy STD3 rules,
  the operation will fail with ParseException
  @return StringBuffer the converted String
  @deprecated ICU 55 Use UTS 46 instead via {@link #getUTS46Instance(int)}.
  @hide original deprecated declaration