def METHOD_NAME(using_opengl_renderer):
    """Test the VGroup __add__ magic method."""
    obj = VGroup()
    assert len(obj.submobjects) == 0
    obj + OpenGLVMobject()
    assert len(obj.submobjects) == 0
    obj += OpenGLVMobject()
    assert len(obj.submobjects) == 1
    with pytest.raises(TypeError):
        obj += OpenGLMobject()
    assert len(obj.submobjects) == 1
    with pytest.raises(TypeError):
        # If only one of the added object is not an instance of OpenGLVMobject, none of them should be added
        obj += (OpenGLVMobject(), OpenGLMobject())
    assert len(obj.submobjects) == 1
    with pytest.raises(ValueError):
        # a OpenGLMobject cannot contain itself
        obj += obj