code: def __len__(self):
      return len(self.annotation)
  
imports: import os, sys
  from collections import OrderedDict
  import random
  from lavis.datasets.datasets.base_dataset import BaseDataset
  from lavis.common.utils import is_serializable
  from PIL import Image
  import numpy
  from tqdm import tqdm
  import json
  import torch
  import copy
label_desc: Use image node_id 9 for calling the Object3dCaptionDataset obj's underlying member method code with example usage: obj.__len__() and returns: len