code: public static String hexDump(final DirectBuffer buffer, final int fromIndex, final int length)
      {
          return HexUtil.hexDump(buffer, fromIndex, length);
      }
docs: Returns a <a href="http://en.wikipedia.org/wiki/Hex_dump">hex dump</a>
  of the specified buffer's sub-region.
  
  @param buffer    dumped buffer
  @param fromIndex where should we start to print
  @param length    how much should we print
  @return hex dump in a string representation