ChunkedConversionSink<Object> startChunkedConversion(Sink<String> sink)

Starts a chunked conversion.

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

Returns a chunked-conversion sink that accepts at most one object. It is an error to invoke add more than once on the returned sink.

Source 

ChunkedConversionSink<Object> startChunkedConversion(Sink<String> sink) {
  if (sink is! StringConversionSink) {
    sink = new StringConversionSink.from(sink);
  } else if (sink is _Utf8EncoderSink) {
    return new _JsonUtf8EncoderSink(sink._sink, _toEncodable,
                                    JsonUtf8Encoder._utf8Encode(indent),
                                    JsonUtf8Encoder.DEFAULT_BUFFER_SIZE);
  }
  return new _JsonEncoderSink(sink, _toEncodable, indent);
}