code: def __post_init__(self):
      class_fields = getattr(self, "__dataclass_fields__")
  
      for field in class_fields:
          v = getattr(self, field)
          if v is not None:
              self[field] = v
  
imports: from collections import OrderedDict
  from dataclasses import dataclass
  import tempfile
  import unittest
  import torch
  from torch import nn
  from fairscale.fair_dev.testing.testing import dist_init
  from fairscale.nn import FullyShardedDataParallel
  from fairscale.nn import auto_wrap, enable_wrap
label_desc: Use image node_id 2 for calling the ModelOutput obj's underlying member method code with example usage: obj.__post_init__() without return types