addSlice method

void addSlice (String chunk, int start, int end, bool isLast)
override

Adds the next chunk to this.

Adds the substring defined by start and end-exclusive to this.

If isLast is true closes this.

Implementation 

void addSlice(String chunk, int start, int end, bool isLast) {
  if (_isClosed) {
    throw new StateError("Can't add to a closed sink.");
  }

  _buffer.write(chunk.substring(start, end));
  if (isLast) _isClosed = true;
}