def get_installed_pypackages():
    return {p.project_name.lower(): p for p in pkg_resources.working_set}
def visitdir(self, dir):
        dir = normalizerootdir(dir, "visitdir")
        visit1 = self._m1.visitdir(dir)
        if visit1 == "all":
            return self._m2.visitdir(dir)
        # bool() because visit1=True + visit2='all' should not be 'all'
        return bool(visit1 and self._m2.visitdir(dir))