docs: private static final boolean isHeaderEnd(StringBuilder sb) {
  		int len = sb.length();
  		if (len > 2) {
  			if (LF2.equals(sb.substring(len-2))) {
  				return true;
  			}
  		}
  	
  		if (len > 4) {
  			if (CRLF2.equals(sb.substring(len-4))) {
  				return true;
  			}
  		}
  	
  		return false;
  	}