def save(self, doc):
        if doc.id:
            return self.update(doc)
        else:
            return self.insert(doc)
def matchfn(self, f):
        # Some information is lost in the superclass's constructor, so we
        # can not accurately create the matching function for the subdirectory
        # from the inputs. Instead, we override matchfn() and visitdir() to
        # call the original matcher with the subdirectory path prepended.
        return self._matcher.matchfn(self._path + "/" + f)