@classmethod
    def open(cls, pkg_file=None):
        if pkg_file is None:
            pkg_file = cls._default_pptx_path
        return super(Package, cls).open(pkg_file)
List discovered extension classes. Optionally, only list extensions of a
dataset/ETHPy150Open scanny/python-pptx/pptx/package.py/Package.open--crossover with--dataset/ETHPy150Open ARM-software/workload-automation/wlauto/core/extension_loader.py/ExtensionLoader.list_extensions