.add("field1", "Hello")
            .add("field2", CharBuffer.allocate(0))
            .toString();
    assertThat(toTest).isEqualTo("TestClass{field1=Hello}");
  }

  public void testToStringHelperWithArrays() {
    String[] strings = {"hello", "world"};
    int[] ints = {2, 42};
    Object[] objects = {"obj"};
    @Nullable String[] arrayWithNull = new @Nullable String[] {null};
    Object[] empty = {};