class_docstr: A callback that runs a list of :class:`Inferencer` on some :class:`InputSource`.
code: def _trigger(self):
      for inf in self.infs:
          inf.before_epoch()
  
      self._input_source.reset_state()
      # iterate over the data, and run the hooked session
      with _inference_context(), tqdm.tqdm(
          total=self._size, **get_tqdm_kwargs()
      ) as pbar:
          num_itr = self._size if self._size > 0 else sys.maxsize
          for _ in range(num_itr):
              self._hooked_sess.run(fetches=[])
              pbar.update()
      for inf in self.infs:
          inf.trigger_epoch()
  
imports: import itertools
  import sys
  from contextlib import contextmanager
  import tqdm
  from tensorflow.python.training.monitored_session import _HookedSession
  from ..compat import tfv1
  from ..dataflow.base import DataFlow
  from ..input_source import FeedInput, InputSource, QueueInput, StagingInput
  from ..tfutils.tower import PredictTowerContext
  from ..utils import logger
  from ..utils.utils import get_tqdm_kwargs
  from .base import Callback
  from .group import Callbacks
  from .inference import Inferencer
label_desc: Use image node_id 4 for calling the InferenceRunner obj's underlying member method code with example usage: obj._trigger() without return types