@Test
  public void testDeleteEntity() {

    TestEntity t = new TestEntity();
    t.setStringProperty(String.format("Hello World!"));

    repository.save(t);
    repository.delete(Arrays.asList(t));

    TestEntity actual = repository.findById(t.getId());

    assertNull("Checking that the result is null.", actual);
  }
  @Test
  public void testDeleteAllEntities() {

    TestEntity t1 = new TestEntity();
    t1.setStringProperty(String.format("1"));

    TestEntity t2 = new TestEntity();
    t2.setStringProperty(String.format("2"));

    repository.save(Arrays.asList(t1, t2));
    repository.deleteAll();

    assertNull("Checking that the result is null.", repository.findById(t1.getId()));
    assertNull("Checking that the result is null.", repository.findById(t2.getId()));
  }