class_docstr: Base class of Inferencer.
  Inferencer is a special kind of callback that should be called by :class:`InferenceRunner`.
  It has the methods ``_get_fetches`` and ``_on_fetches`` which are like
  :class:`SessionRunHooks`, except that they will be used only by :class:`InferenceRunner`.
  
  .. document private functions
  .. automethod:: _before_inference
  .. automethod:: _after_inference
  .. automethod:: _get_fetches
  .. automethod:: _on_fetches
docstr: Called after a round of inference ends.
  Returns a dict of scalar statistics which will be logged to monitors.
code: def _after_inference(self):
      """
      Called after a round of inference ends.
      Returns a dict of scalar statistics which will be logged to monitors.
      """
      pass
  
imports: import numpy
  from abc import ABCMeta
  import six
  from ..tfutils.common import get_op_tensor_name
  from ..utils import logger
  from ..utils.stats import BinaryStatistics, RatioCounter
  from .base import Callback
label_desc: Use image node_id 4 for calling the Inferencer obj's underlying member method code with example usage: obj._after_inference() without return types