return suite;
  }

  private ClassToInstanceMap<Number> map;

  @Override
  protected void setUp() throws Exception {
    map = MutableClassToInstanceMap.create();
  }

  public void testConstraint() {
    /*
     * We'll give ourselves a pass on testing all the possible ways of breaking the constraint,
     * because we know that newClassMap() is implemented using ConstrainedMap which is itself