}
    }

  fun override(
    encoding: Encoding,
    vararg codePoints: Int,
  ) = apply {
    for (codePoint in codePoints) {
      encodings[codePoint] = encoding
    }
  }

  fun nonPrintableAscii(encoding: Encoding) =
    apply {
      encodings[ 0x0] = encoding // Null character
      encodings[ 0x1] = encoding // Start of Header
      encodings[ 0x2] = encoding // Start of Text

    // lock it down due to URL templating: "http://{env}.{dc}.example.com".
    UrlComponentEncodingTester
      .newInstance()
      .nonPrintableAscii(Encoding.FORBIDDEN)
      .nonAscii(Encoding.PUNYCODE)
      .override(
        Encoding.FORBIDDEN,
        '\t'.code,
        '\n'.code,
        '\u000c'.code,
        '\r'.code,
        ' '.code,