not working for a big xml file

[Euphorbium]

try to scrape https://www.redbubble.com/sitemap/works-00001.xml and get the links

Python 3.6.4 (default, Sep 28 2018, 21:53:06) 
[GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from requests_xml import XMLSession
>>> session = XMLSession()
>>> sitemap = session.get("https://www.redbubble.com/sitemap/works-00001.xml")
>>> sitemap.xml.links
[]
>>> sitemap.xml.xpath('//url')
[]