code: static int readInt(final byte[] b, final int index) {
          return ((b[index] & 0xFF) << 24) | ((b[index + 1] & 0xFF) << 16)
                  | ((b[index + 2] & 0xFF) << 8) | (b[index + 3] & 0xFF);
      }
docs: Reads a signed int value in the given byte array.
  
  @param b a byte array.
  @param index the start index of the value to be read.
  @return the read value.