code: public static long toLong(byte[]buf, int off) {
          return ((long)(toInt(buf, off)) << 32) + (toInt(buf, off+4) & 0xFFFFFFFFL);
      }
docs: Converts 8 bytes to a <code>long</code> at the
  specified offset in the given byte array.
  
  @param buf the byte array containing the 8 bytes
  to be converted to a <code>long</code>.
  @param off offset in the byte array
  @return the <code>long</code> value of the 8 bytes.