code: def __len__(self):
      return len(self.dataset)
  
file_path: BigDL/python/nano/src/bigdl/nano/deps/openvino/pytorch/dataloader.py
imports: from openvino.tools.pot import DataLoader
  from torch.utils.data.dataloader import DataLoader
  from bigdl.nano.utils.common import invalidInputError
label_desc: Use image node_id 3 for calling the PytorchOpenVINODataLoader obj's underlying member method code with example usage: obj.__len__() and returns: len