code: def get_optimizer(opt):
      if opt == "sgd":
          return optim.SGD
      elif opt == "adam":
          return optim.Adam
      else:
          raise NotImplementedError
  
file_path: dgl/examples/pytorch/gcmc/utils.py
imports: import csv
  import re
  from collections import OrderedDict
  import numpy
  import torch
  import torch.nn
  import torch.optim
label_desc: Use image node_id 4 for calling a global function with example usage: get_optimizer(opt) and returns: optim, optim