@Test
public void testUniqueEditDirs() throws IOException {

  Configuration config = new Configuration();
  config.set(DFS_NAMENODE_EDITS_DIR_KEY, "file://edits/dir, "
      + "file://edits/dir1,file://edits/dir1"); // overlapping internally
  // getNamespaceEditsDirs removes duplicates
  Collection<URI> editsDirs = FSNamesystem.getNamespaceEditsDirs(config);
  assertEquals(2, editsDirs.size());
}