def _late_init(self, task):
        """ Gets called after the pipeline got initialized """
        scene_tex = self._pipeline.stage_mgr.pipes["ShadedScene"]
        self._zoomer.set_shader(
            RPLoader.load_shader("/$$rp/shader/default_gui_shader.vert.glsl", "/$$rp/shader/pixel_inspector.frag.glsl")
        )
        self._zoomer.set_shader_input("SceneTex", scene_tex)
        return task.done
 Gets called after the pipeline got initialized 
metadrive/render_pipeline/rpcore/gui/pixel_inspector.py