Python libxml2: xpathEval vs xpathEval2? -

in libxml2 found that:

xpatheval(self, expr)       # selecting nodes using xpath, bit slow because context       # allocated/freed every time convenient.  xpatheval2(self, expr) 

it confusing xpatheval2 doesn't include further comment. difference among them?

in version there no difference, @ python code:

    def xpatheval2(self, expr):       return self.xpatheval(expr) 

but there's section commented out shows method intended speeding parsing, though had memory leaks:

#    # selecting nodes using xpath, faster because context #    # allocated once per xmldoc. #    # #    # removed: dv memleaks c.f. #126735 

check implementation more accurate info.