code: def __len__(self):
      return len(self.params)
  
file_path: pytorch-toolbelt/pytorch_toolbelt/optimization/functional.py
imports: import dataclasses
  import numbers
  from typing import Optional, Iterator, Dict, Union, List, Tuple, Mapping
  from torch import nn
  from pytorch_toolbelt.utils.distributed import get_rank, get_world_size, is_dist_avail_and_initialized
  from pytorch_toolbelt.utils.torch_utils import get_non_wrapped_model
label_desc: Use image node_id 1 for calling the ParametersGroup obj's underlying member method code with example usage: obj.__len__() and returns: len