private Set<String> getExpectedPathes(String... fileNames) {
    Set<String> expectedPathes = new HashSet<>();
    for (String fileName : fileNames) {
      expectedPathes.add("/sometestpath/" + fileName);
    }
    return expectedPathes;
  }
This test tests that Utilities.get*Tasks do not repeat themselves in the process
of extracting tasks from a given set of root tasks when given DAGs that can have
multiple paths, such as the case with Diamond-shaped DAGs common to replication.
ql/src/test/org/apache/hadoop/hive/ql/exec/TestUtilities.java