def load_installed_version(self):
        installed_packages = get_installed_pypackages()
        if self.package in installed_packages:
            self.version = "=={}".format(
                installed_packages[self.package].version)
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)