docs: public static final String toHex(byte[] buf)
      {
          StringBuilder sb = new StringBuilder();
          int prec = prec(buf.length);
          for (int ii=0;ii<prec;ii++)
          {
              sb.append(' ');
          }
          sb.append("  ");
          String format = "%0"+prec+"x: ";
          sb.append(Title);
          sb.append('\n');
          for (int ii=0;ii<buf.length;ii+=16)
          {
              printLine(sb, format, buf, ii, Math.min(16, buf.length - ii));
          }
          return sb.toString();
      }