def _apply_future_bindings(self):
        """ Applies all future bindings. At this point all pipes and
        inputs should be present """
        for pipe, stage in self.future_bindings:
            if pipe not in self.pipes:
                self.error("Could not bind future pipe:", pipe, "not present!")
                continue
            stage.set_shader_input(pipe, self.pipes[pipe])
        self.future_bindings = []
 Applies all future bindings. At this point all pipes and
        inputs should be present 
metadrive/render_pipeline/rpcore/stage_manager.py