): T {
    val previous = Locale.getDefault()
    try {
      Locale.setDefault(locale)
      return block()
    } finally {
      Locale.setDefault(previous)
    }
  }

  @Test fun testIllegalCharsetName() {
    val mediaType = parse("text/plain; charset=\"!@#$%^&*()\"")
    assertNull(mediaType.charsetName())
  }

  @Test fun testUnsupportedCharset() {
    val mediaType = parse("text/plain; charset=utf-wtf")