def get_installed_pypackages():
    return {p.project_name.lower(): p for p in pkg_resources.working_set}
def files(self):
        """Explicitly listed files or patterns or roots:
        if no patterns or .always(): empty list,
        if exact: list exact files,
        if not .anypats(): list all files and dirs,
        else: optimal roots"""
        return self._files