code: public ISynchronizationPoint<IOException> write(char c) {
  		if (!(stream instanceof ICharacterStream.Writable.Buffered))
  			return write(new char[] { c }, 0, 1);
  		ISynchronizationPoint<IOException> last = lastWrite;
  		if (last.isUnblocked()) {
  			lastWrite = ((ICharacterStream.Writable.Buffered)stream).writeAsync(c);
  			return lastWrite;
  		}
  		SynchronizationPoint<IOException> ours = new SynchronizationPoint<>();
  		lastWrite = ours;
  		last.listenInline(() -> { ((ICharacterStream.Writable.Buffered)stream).writeAsync(c).listenInline(ours); }, ours);
  		return ours;
  	}
docs: Write a single character.