code: def _build_extra_inputs(self, train=True):
      if train:
          self._add_input(
              name="labels", dtype="float32", shape=[self._batch_size]
          )
      else:
          self._add_input(name="labels", dtype="none", train=False)
  
file_path: openrec/openrec/tf1/legacy/recommenders/itr_mlp.py
imports: from __future__ import print_function
  from termcolor import colored
  from openrec.tf1.legacy.recommenders import Recommender
  from openrec.tf1.legacy.modules.extractions import LatentFactor
  from openrec.tf1.legacy.modules.interactions import PointwiseMSE
  from openrec.tf1.legacy.modules.extractions import TemporalLatentFactor
label_desc: Use image node_id 7 for calling the ItrMLP obj's underlying member method code with example usage: obj._build_extra_inputs(train) without return types