code: def save(g, dataset):
      """
      This function saves input dataset to dgl format
      Parameters
      ----------
      g : graph to be saved
      dataset : output folder name
      """
      print("Saving dataset..")
      part_dir = os.path.join("./" + dataset)
      node_feat_file = os.path.join(part_dir, "node_feat.dgl")
      part_graph_file = os.path.join(part_dir, "graph.dgl")
      os.makedirs(part_dir, mode=0o775, exist_ok=True)
      save_tensors(node_feat_file, g.ndata)
      save_graphs(part_graph_file, [g])
      print("Graph saved successfully !!")
  
file_path: dgl/python/dgl/distgnn/tools/tools.py
imports: import os
  import random
  import requests
  import torch
  from scipy.io import mmread
  import dgl
  from dgl.base import DGLError
  from dgl.data.utils import load_graphs, save_graphs, save_tensors
label_desc: Use image node_id 4 for calling a global function with example usage: save(g, dataset) without return types