code: def var_file(self):
      return osp.join(self.output_dir, f"vars.pt")
  
imports: import argparse
  import glob
  import os
  import os.path
  import pprint
  import soundfile
  import torch
  import fairseq
  from torch import nn
  from torch.utils.data import DataLoader
label_desc: Use image node_id 8 for calling the DatasetWriter obj's underlying member method code with example usage: obj.var_file() and returns: osp