class_docstr: pytorch dataset
code: def __len__(self):
      return len(self.dataset)
  
file_path: towhee/towhee/data/dataset/dataset.py
imports: from torch.utils.data.dataset import Dataset
label_desc: Use image node_id 2 for calling the TorchDataSet obj's underlying member method code with example usage: obj.__len__() and returns: len