val buffer = cursor.data
      var i = cursor.start
      val end = cursor.end
      if (buffer != null) {
        while (i < end) {
          keyIndex %= keyLength // Reassign to prevent overflow breaking counter.

          // Byte xor is experimental in Kotlin so we coerce bytes to int, xor them
          // and convert back to byte.
          val bufferInt: Int = buffer[i].toInt()