def METHOD_NAME(self):
    data = loadtxt(
        os.path.join(self.save_path, "{}.txt".format(self.mode)),
        delimiter="\t",
    ).astype(np.int64)
    num_nodes = 23033
    # The source code is not released, but the paper indicates there're
    # totally 137 samples. The cutoff below has exactly 137 samples.
    time_index = np.floor(data[:, 3] / 24).astype(np.int64)
    start_time = time_index[time_index != -1].min()
    end_time = time_index.max()
    self._graphs = []
    for i in range(start_time, end_time + 1):
        row_mask = time_index <= i
        edges = data[row_mask][:, [0, 2]]
        rate = data[row_mask][:, 1]
        g = dgl_graph((edges[:, 0], edges[:, 1]))
        g.edata["rel_type"] = F.tensor(
            rate.reshape(-1, 1), dtype=F.data_type_dict["int64"]
        )
        self._graphs.append(g)