class_docstr: Class for item-to-item recommendations using DKN.
  See https://github.com/microsoft/recommenders/blob/main/examples/07_tutorials/KDD2020-tutorial/step4_run_dkn_item2item.ipynb
code: def _compute_data_loss(self):
      logits = self.pred
      data_loss = -1 * tf.reduce_sum(
          input_tensor=tf.math.log(logits[:, 0] + 1e-10)
      )
      return data_loss
  
file_path: recommenders/recommenders/models/deeprec/models/dkn_item2item.py
imports: import numpy
  import tensorflow
  from recommenders.models.deeprec.models.dkn import DKN
  from recommenders.models.deeprec.deeprec_utils import cal_metric
label_desc: Use image node_id 1 for calling the DKNItem2Item obj's underlying member method code with example usage: obj._compute_data_loss() and returns: data_loss