code: def __len__(self):
      return self.data.shape[0]
  
file_path: labml/samples/stocks/dataset.py
imports: import numpy
  import torch
  from labml import monit, lab
  from labml import tracker
  from torch.utils.data import Dataset
  from stocks import CandleIdx
  from stocks.build_numpy_cache import build_cache
label_desc: Use image node_id 2 for calling the MinutelyDataset obj's underlying member method code with example usage: obj.__len__() and returns: self