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 __init__(self, root, cwd, files, badfn=None):
        super(exactmatcher, self).__init__(root, cwd, badfn)

        if isinstance(files, list):
            self._files = files
        else:
            self._files = list(files)