code: def TokenBucket(
      train,
      batch_size,
      device="cuda:0",
      key=lambda x: max(len(x.word[0]), 5),
  ):
      def batch_size_fn(x, _, size):
          return size + key(x)
  
      return torchtext.data.BucketIterator(
          train,
          train=True,
          sort=False,
          sort_within_batch=True,
          shuffle=True,
          batch_size=batch_size,
          sort_key=lambda x: key(x),
          repeat=True,
          batch_size_fn=batch_size_fn,
          device=device,
      )
  
imports: import torchtext
  import torch
label_desc: Use image node_id 4 for calling a global function with example usage: TokenBucket(train, batch_size, device, key) and returns: torchtext, unknown