Documentation for extract method

[marcelorl]

Something I have noticed. I forgot to add extract documentation.

Also, I see that the extract method returns the url even if there is no query string. I think it should return empty.

What do you think?

[marcelorl]

I actually have already written the code for it. haha

Can I open this one last PR?

[joshghent]

@marcelorl Absolutely! Would love to have the contribution