While working on the DevTools profiler, I've noticed that durations are sometimes incorrect. This seems to be vaguely related to high/low priority state updates. Need to track this down more so I'm filing an issue for myself.
}
      invariant(
        false,
        'Element type is invalid: expected a string (for built-in ' +
          'components) or a class/function (for composite components) ' +
          'but got: %s.%s',
        type == null ? type : typeof type,
        info,
      );
    }
  }
}
export function createFiberFromFragment(
  elements: ReactFragment,
  mode: TypeOfMode,
  expirationTime: ExpirationTime,
  key: null | string,
): Fiber {
  const fiber = createFiber(Fragment, elements, key, mode);
  fiber.expirationTime = expirationTime;
  return fiber;
}
export function createFiberFromProfiler(
  pendingProps: any,
  mode: TypeOfMode,
  expirationTime: ExpirationTime,
  key: null | string,
): Fiber {
  if (__DEV__) {
    if (