class Data:
    def __init__(self, *args, **kwargs):
        raise NotImplementedError("torch_geometric is not installed in this inference-only demo.")


class InMemoryDataset:
    def __init__(self, *args, **kwargs):
        raise NotImplementedError("torch_geometric is not installed in this inference-only demo.")


def download_url(*args, **kwargs):
    raise NotImplementedError("torch_geometric is not installed in this inference-only demo.")