// six-per-em space
    assertThat(parse("http://h/\u2006").encodedPath).isEqualTo("/%E2%80%86")
    // figure space
    assertThat(parse("http://h/\u2007").encodedPath).isEqualTo("/%E2%80%87")
    // punctuation space
    assertThat(parse("http://h/\u2008").encodedPath).isEqualTo("/%E2%80%88")
    // thin space
    assertThat(parse("http://h/\u2009").encodedPath).isEqualTo("/%E2%80%89")
    // hair space

  fun validateKey(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)
    var key = ""
    assertFailsWith<IllegalArgumentException> {
      key = "has_space "
      cache.edit(key)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("keys must match regex [a-z0-9_-]{1,120}: \"$key\"")
    }
    assertFailsWith<IllegalArgumentException> {

 *
 * Neither of the built-in URL models offer direct access to path segments or query parameters.
 * Manually using `StringBuilder` to assemble these components is cumbersome: do '+' characters get
 * silently replaced with spaces? If a query parameter contains a '&', does that get escaped?
 * By offering methods to read and write individual query parameters directly, application
 * developers are saved from the hassles of encoding and decoding.
 *