assertEqualCharNodes(traverser.depthFirstPreOrder(charactersOf("bd")), "bcda");
    assertEqualCharNodes(traverser.depthFirstPreOrder(charactersOf("dc")), "dabc");
    assertEqualCharNodes(traverser.depthFirstPreOrder(charactersOf("bc")), "bcda");
  }

  @Test
  public void forGraph_depthFirstPreOrder_twoCycles() {

    // These have a combination of invalid length, unrecognized characters and wrong padding.
    assertFailsToDecode(base32(), "AB=C", "Unrecognized character: =");
    assertFailsToDecode(base32(), "A=BCDE", "Invalid input length 6");
    assertFailsToDecode(base32(), "?", "Invalid input length 1");
  }

  public void testBase32UpperCaseIsNoOp() {
    assertThat(base32().upperCase()).isSameInstanceAs(base32());
  }

  <mime-type type="application/x-cdf">
    <_comment>CD Audio</_comment>
    <magic priority="50">
      <match value="RIFF$\x00\x00\x00CDDAfmt\x20\x18" type="string" offset="0" />
      <glob pattern="*.cda"/>
    </magic>
  </mime-type>
  <mime-type type="application/x-gtar">
    <_comment>GNU tar Compressed File Archive (GNU Tape Archive)</_comment>
    <magic priority="50">
      <!-- GNU tar archive -->