docs: public static String readLine(ByteBuffer buffer, Charset charset) {
  		final int startPosition = buffer.position();
  		final int endPosition = lineEnd(buffer);
  
  		if (endPosition > startPosition) {
  			byte[] bs = readBytes(buffer, startPosition, endPosition);
  			return StrUtil.str(bs, charset);
  		} else if (endPosition == startPosition) {
  			return StrUtil.EMPTY;
  		}
  
  		return null;
  	}