Doesn't work with new versions of python (e.g. python 3.10)

[talwrii]

Describe the bug

Errors out complaining about Iterator and collections.

To Reproduce

Use the library with python3.10

Expected behavior

Not erroring out

** Additional context **

This is fixed in #1

[S0AndS0]

Thanks, changes have been merged!

If everything, including the recent changes I added to preserve backwards compatibility, be acceptable then feel free to close this issue.

Note regarding pdf-utilities/inject_javascript Pull Request; I'm gonna have to find time to ponder a bit more on how to cleanly accommodate old versions of Python, and dependencies, so know that I ain't ignoring ya over there.