code: def _infer_iter_generator():
      """
      This generator yields infinite number of infer iterations.
  
      :return: iteration message instances
      """
      infer_iterations = _iter_msg_generator(itertools.count(), INFER)
      for infer_iter_msg in infer_iterations:
          yield infer_iter_msg
  
imports: import itertools
  import time
  from niftynet.engine.application_variables import CONSOLE, TF_SUMMARIES
  from niftynet.engine.signal import TRAIN, VALID, INFER
  from niftynet.utilities.util_common import look_up_operations
label_desc: Use image node_id 1 for calling a global function with example usage: _infer_iter_generator() without return types