StringConversionSink startChunkedConversion(Sink<List<int>> sink)

Starts a chunked conversion.

The converter works more efficiently if the given sink is a ByteConversionSink.

Source 

StringConversionSink startChunkedConversion(Sink<List<int>> sink) {
  if (sink is! ByteConversionSink) {
    sink = new ByteConversionSink.from(sink);
  }
  return new _UnicodeSubsetEncoderSink(_subsetMask, sink);
}