code: def __len__(self):
      return self.total_samples
  
imports: import torch
  import os
  import numpy
  import deepspeed.comm
  from deepspeed.utils import logger
  from deepspeed.accelerator import get_accelerator
  from ..constants import *
  from ..curriculum_scheduler import CurriculumScheduler
  from .indexed_dataset import MMapIndexedDataset
  from .utils import create_mmap_dataset_builder, close_mmap_dataset_builder, find_fit_int_dtype
label_desc: Use image node_id 2 for calling the DeepSpeedDataSampler obj's underlying member method code with example usage: obj.__len__() and returns: self