public void testNulls() throws Exception {
    IssueTypeKeyComparator issueTypeKeyComparator = new IssueTypeKeyComparator(null);

    assertEquals(0, issueTypeKeyComparator.compare(null, null));
    assertEquals(-1, issueTypeKeyComparator.compare(null, "qwe"));
    assertEquals(1, issueTypeKeyComparator.compare("qwe", null));
  }
  public void testSequence() throws Exception {
    MockConstantsManager mockConstantsManager = new MockConstantsManager();
    IssueType it1 = mockConstantsManager.insertIssueType("Improvement", 1L, null, "...", null);
    IssueType it2 = mockConstantsManager.insertIssueType("Bug", 2L, null, "...", null);
    IssueType it3 = mockConstantsManager.insertIssueType("Custom", null, null, "...", null);

    IssueTypeKeyComparator issueTypeKeyComparator =
        new IssueTypeKeyComparator(mockConstantsManager);
    assertEquals(0, issueTypeKeyComparator.compare(it1.getId(), it1.getId()));
    assertEquals(-1, issueTypeKeyComparator.compare(it1.getId(), it2.getId()));
    assertEquals(1, issueTypeKeyComparator.compare(it2.getId(), it1.getId()));

    assertEquals(0, issueTypeKeyComparator.compare(it3.getId(), it3.getId()));
    assertEquals(1, issueTypeKeyComparator.compare(it1.getId(), it3.getId()));
    assertEquals(-1, issueTypeKeyComparator.compare(it3.getId(), it1.getId()));
  }