code: def __len__(self):
      if self.drop_last:
          return len(self.lengths) // self.batch_size
      else:
          return len(self.lengths) // self.batch_size + (
              len(self.lengths) % self.batch_size > 0
          )
  
file_path: llama-recipes/src/llama_recipes/data/sampler.py
imports: import random
  from itertools import islice
  import numpy
  import torch
label_desc: Use image node_id 3 for calling the LengthBasedBatchSampler obj's underlying member method code with example usage: obj.__len__() and returns: unknown, unknown