Implement ends-with in xmerl

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Is your feature request related to a problem? Please describe.
I want to be able to locate <loc> entries that ends with .xml

Describe the solution you'd like
I hope xmerl can implement ends-with according to the XPath2 spec https://www.w3.org/2005/xpath-functions/

Describe alternatives you've considered
/urlset/url[loc[not(substring(., string-length(.) - 3) = '.xml')]]/loc/text() but substring is also not implemented

Thanks!