code: def test_compute_loss(self):
      test_loss = self.art_model.compute_loss(
          self.x_test_diabetes[:4],
          self.y_test_diabetes[:4].astype(np.float32),
      )
      np.testing.assert_equal(len(np.unique(test_loss)), 4)
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import unittest
  import numpy
  from art.estimators.regression.keras import KerasRegressor
  from tests.utils import TestBase, master_seed, get_tabular_regressor_kr
label_desc: Use image node_id 8 for calling the TestKerasRegressorFunctional obj's underlying member method code with example usage: obj.test_compute_loss() without return types