w *= scaleW
      }
      bias = adapt(i - oldi, codePoints.size + 1, oldi == 0)
      val deltaN = i / (codePoints.size + 1)
      if (n > Int.MAX_VALUE - deltaN) return false // Prevent overflow.
      n += deltaN
      i %= (codePoints.size + 1)

      if (n > 0x10ffff) return false // Not a valid code point.

      codePoints.add(i, n)

      i++