code: def __len__(self):
      if self.n is None:
          raise TypeError
      if self.bs is None:
          return self.n
      return self.n // self.bs + (
          0 if self.drop_last or self.n % self.bs == 0 else 1
      )
  
imports: from __future__ import annotations
  from ..torch_basics import *
  from torch.utils.data.dataloader import _MultiProcessingDataLoaderIter, _SingleProcessDataLoaderIter, _DatasetKind
label_desc: Use image node_id 2 for calling the DataLoader obj's underlying member method code with example usage: obj.__len__() and returns: unknown, self