@Test
public void testRehash() {

  set.add("hei");
  set.add("hei2");
  set.add("hei3");
  set.add("hei4");
  set.add("bei");
  set.add("bei2");
  set.add("bei3");
  set.add("bei4");
  set.add("_hei");
  set.add("_hei2");
  set.add("_hei3");
  set.add("_hei4");
  set.add("_bei");
  set.add("_bei2");
  set.add("_bei3");
  set.add("_bei4");
  set.add("$_hei");
  set.add("$_hei2");
  set.add("$_hei3");
  set.add("$_hei4");
  set.add("$_bei");
  set.add("$_bei2");
  set.add("$_bei3");
  set.add("$_bei4");
  Assert.assertTrue("set(24).size() != 24", set.size() == 24);
  Assert.assertTrue("contained object lost", set.contains("hei"));
  Assert.assertTrue("contained object lost", set.contains("hei2"));
  Assert.assertTrue("contained object lost", set.contains("hei3"));
  Assert.assertTrue("contained object lost", set.contains("hei4"));
  Assert.assertTrue("contained object lost", set.contains("_hei"));
  Assert.assertTrue("contained object lost", set.contains("_hei2"));
  Assert.assertTrue("contained object lost", set.contains("_hei3"));
  Assert.assertTrue("contained object lost", set.contains("_hei4"));
  Assert.assertTrue("contained object lost", set.contains("$_hei"));
  Assert.assertTrue("contained object lost", set.contains("$_hei2"));
  Assert.assertTrue("contained object lost", set.contains("$_hei3"));
  Assert.assertTrue("contained object lost", set.contains("$_hei4"));
}