fn cleanup_swapchain(&self) {
        unsafe {
            for framebuffer in self.framebuffers.borrow().iter() {
                self.device.destroy_framebuffer(*framebuffer, None);
            }

            self.device.free_command_buffers(self.command_pool, &self.command_buffers.borrow());

            self.device.destroy_pipeline(*self.pipeline.borrow(), None);
            self.device.destroy_pipeline_layout(*self.pipeline_layout.borrow(), None);
            self.device.destroy_render_pass(*self.render_pass.borrow(), None);
            for image_view in self.image_views.borrow().iter() {
                self.device.destroy_image_view(*image_view, None);
            }

            self.swapchain_ext.destroy_swapchain(*self.swapchain.borrow(), None);
            println!("Swapchain destroyed!");
        }
    }