63     """
     64     Get configured storage backend instance.
     65 
   (...)
     70         StorageBackendNotFoundError: If specified backend type is not supported
     71     """
---> 73     backend_type: str = self.config["storage_backend"]
     75     if backend_type == "file":
     76         return FileStorage(base_path=self.BASE_DIRECTORY)

AttributeError: 'Config' object has no attribute 'config'``````