code: static public void appendHexString(StringBuilder buffer, long value) {
          appendHexString(buffer, (int)((value & 0xFFFFFFFF00000000L) >>> 32));
          appendHexString(buffer, (int)(value & 0x00000000FFFFFFFFL));
      }
docs: Appends 16 characters to a StringBuilder with the long in a "Big Endian"
  hexidecimal format. For example, a long 0xAABBCCDDEE123456 will be appended as a
  String in format "AABBCCDDEE123456". A long of value 0 will be appended as "0000000000000000".
  @param buffer The StringBuilder the long value in hexidecimal format
  will be appended to.  If the buffer is null, this method will throw
  a NullPointerException.
  @param value The long value that will be converted to a hexidecimal String.