* G_DEFINE_TYPE (MyExampleImpl, my_example_impl, MY_TYPE_EXAMPLE);
* g_io_extension_point_implement ("my-extension-point",
* my_example_impl_get_type (),
* G_DEFINE_TYPE (MyExampleImpl, my_example_impl, MY_TYPE_EXAMPLE);
* g_io_extension_point_implement ("my-extension-point",
* my_example_impl_get_type (),