code: def transition_iterator(
      environment: dm_env.Environment,
  ) -> Callable[[int], Iterator[types.Transition]]:
      """Constructs fake iterator of transitions.
  
      Args:
        environment: Constructed fake transitions will match the specification of
          this environment.
  
      Returns:
        A callable that given a batch_size returns an iterator of transitions.
      """
      return transition_iterator_from_spec(
          specs.make_environment_spec(environment)
      )
  
imports: import threading
  from typing import List, Mapping, Optional, Sequence, Callable, Iterator
  from acme import core
  from acme import specs
  from acme import types
  from acme import wrappers
  import dm_env
  import numpy
  import reverb
  from rlds import rlds_types
  import tensorflow
  import tree
label_desc: Use image node_id 7 for calling a global function with example usage: transition_iterator(environment) and returns: transition_iterator_from_spec