class_docstr: A predictor which directly use an existing session and given tensors.
  
  Attributes:
      sess: The tf.Session object associated with this predictor.
code: def _do_call(self, dp):
      assert len(dp) == len(self.input_tensors), "{} != {}".format(
          len(dp), len(self.input_tensors)
      )
      if self.sess is None:
          self.sess = tf.get_default_session()
          assert (
              self.sess is not None
          ), "Predictor isn't called under a default session!"
  
      if self._callable is None:
          self._callable = self.sess.make_callable(
              fetches=self.output_tensors,
              feed_list=self.input_tensors,
              accept_options=self.ACCEPT_OPTIONS,
          )
      # run_metadata = tf.RunMetadata()
      # options = tf.RunOptions(trace_level=tf.RunOptions.FULL_TRACE)
      return self._callable(*dp)
  
imports: from abc import ABCMeta, abstractmethod
  import six
  import tensorflow
  from ..input_source import PlaceholderInput
  from ..tfutils.common import get_tensors_by_names, get_op_tensor_name
  from ..tfutils.tower import PredictTowerContext
label_desc: Use image node_id 2 for calling the OnlinePredictor obj's underlying member method code with example usage: obj._do_call(dp) and returns: self