  img.onerror = e => { reject("The img should not fail to load") };

    document.querySelector('#below-viewport-img-container').append(img);
    img.src = image_path;
  });
  const timeout_promise = new Promise((resolve, reject) => {
    t.step_timeout(() => {
      reject(new Error("The `loading=lazy` image should load immediately from " +
                       "the list of available images, beating this timeout " +
                       "promise."));
    }, 1000);
  });

  // The `lazyload_image_promis