corrected docstring

[smcoll]

The final allowed type is 'content'.

What do you think about raising a ValueError if type is not in a list of valid options, similar to the implementation of allowed_extensions in get_document_content()?

[caxap]

I believe that actual type list can be changed in future. So I will be a little bit painful to track these changes. And that's why I've decided to not add such check.

[smcoll]

Alright, that makes sense.

[caxap]

Actually download link has next format https://view-api.box.com/1/sessions/17eb5a85a857467f92b3da5b3c2dd3dd/content. As you can see, it has content trailer.

So we need leave content, or add extra check for download. Something like this:

type = 'content' if type == 'download' else type

[smcoll]

Not sure if i follow; are you saying the API used to have a /download endpoints that was renamed /content? If so, yeah, that conversion might be helpful.