Hi @micred, I've done something in the `lazyload` branch. 

Now I've got empty frames dumped when `split-pages=1`, and there is an extra property `data-page-url` for them. I didn't output the `ctm` for them, since I guess it would not be necessary? But for the jumping function, it should wait for the page loaded before it try to use ctm.

How do you think about it?

I think we need a new pull request to that branch, since the program would break in the middle of the implementation. I'm not sure if we can modify the existing pull request. Can you please close this one and open a new one?