Search in the Variable array of the context for the given
           variable value.

def xpathVariableLookup(self, name):
        """Search in the Variable array of the context for the given
           variable value. """
        ret = libxml2mod.xmlXPathVariableLookup(self._o, name)
        if ret is None:raise xpathError('xmlXPathVariableLookup() failed')
        return xpathObjectRet(ret)