assertFailsToDecode(base32Hex(), "A");
    assertFailsToDecode(base32Hex(), "ABC");
    assertFailsToDecode(base32Hex(), "ABCDEF");
  }

  public void testBase32HexUpperCaseIsNoOp() {
    assertThat(base32Hex().upperCase()).isSameInstanceAs(base32Hex());
  }

  public void testBase16() {
    testEncodingWithCasing(base16(), "", "");
    testEncodingWithCasing(base16(), "f", "66");