*
   * [RFC 3491]: https://datatracker.ietf.org/doc/html/rfc3491
   */
  fun readNameprep(base: Path): Stringprep {
    val unassigned = readCodePointSet(base / "rfc3454.A.1.txt")
    val mapping =
      MappingListCodePointMapping(
        mutableMapOf<Int, String>()
          .apply {
            putAll(readCodePointMapping(base / "rfc3454.B.1.txt").mappings)
            putAll(readCodePointMapping(base / "rfc3454.B.2.txt").mappings)

    val nameprep = reader.readNameprep("/okhttp3/internal/idn".toPath())
    assertThat((nameprep.unassigned as RangeListCodePointSet).ranges).hasSize(396)
    assertThat((nameprep.mapping as MappingListCodePointMapping).mappings).hasSize(1398)
    assertThat((nameprep.prohibitSet as RangeListCodePointSet).ranges).hasSize(78)
    assertThat((nameprep.randalcatSet as RangeListCodePointSet).ranges).hasSize(34)