async function createNestedEscControllers(parentContent) {
  const childContent = /** @type {HTMLDivElement} */ (parentContent.querySelector('div[id]'));
  // Assert valid fixure
  const isValidFixture =
    (parentContent.id.startsWith('parent-overlay--hidesOnEsc') ||
      parentContent.id.startsWith('parent-overlay--hidesOnOutsideEsc')) &&
    (childContent.id.startsWith('child-overlay--hidesOnEsc') ||
      childContent.id.startsWith('child-overlay--hidesOnOutsideEsc'));
  if (!isValidFixture) {
    throw new Error('Provide a valid fixture');
  }

  if (parentContent.hasAttribute('data-convert-to-shadow-root')) {
    const shadowRootParent = parentContent.attachShadow({ mode: 'open' });
    shadowRootParent.appendChild(childContent);
  }

  const parentHasOutsideOnEsc = parentContent.id.startsWith('parent-overlay--hidesOnOutsideEsc');
  const childHasOutsideOnEsc = childContent.id.startsWith('child-overlay--hidesOnOutsideEsc');

  const parentConfig = parentHasOutsideOnEsc ? { hidesOnOutsideEsc: true } : { hidesOnEsc: true };
  const childConfig = childHasOutsideOnEsc ? { hidesOnOutsideEsc: true } : { hidesOnEsc: true };

  const parentOverlay = new OverlayController({
    ...withGlobalTestConfig(),
    contentNode: parentContent,
    ...parentConfig,
  });
  const childOverlay = new OverlayController({
    ...withGlobalTestConfig(),
    contentNode: childContent,
    ...childConfig,
  });

  await parentOverlay.show();
  await childOverlay.show();

  return { parentOverlay, childOverlay };
}
@param {HTMLDivElement} parentContent
@returns {Promise<{parentOverlay: OverlayController; childOverlay: OverlayController}>}