@property
    def _app(self):
        """The application object to work with; this is either the app
        that we have been bound to, or the current application.
        """
        if self.app is not None:
            return self.app

        ctx = _request_ctx_stack.top
        if ctx is not None:
            return ctx.app

        try:
            from flask import _app_ctx_stack
            app_ctx = _app_ctx_stack.top
            if app_ctx is not None:
                return app_ctx.app
        except __HOLE__:
            pass

        raise RuntimeError('assets instance not bound to an application, '+
                            'and no application in current context')



    # XXX: This is required because in a couple of places, webassets 0.6
    # still access env.directory, at one point even directly. We need to
    # fix this for 0.6 compatibility, but it might be preferrable to
    # introduce another API similar to _normalize_source_path() for things
    # like the cache directory and output files.
dataset/ETHPy150Open miracle2k/flask-assets/src/flask_assets.py/Environment._app