Methods are not avilable

[giugent]

I'm installed in Windows 10 with Pyhton 2.7 via pip command: python -m pip install quadkey
This is the result; Successfully installed quadkey-0.0.5
In my python script I import it: import quadkey
Unfortuately the methods reported in the description are not available.
For example I would like to use the method tile2bbox_webmercator.
Any help would be appreciated.