code: def test_loss_gradient(self):
      grad = self.art_model.loss_gradient(
          self.x_test_diabetes[:4], self.y_test_diabetes[:4]
      )
      grad_expected = [
          -333.9,
          586.4,
          -1190.9,
          -123.9,
          -1206.2,
          -883.7,
          295.9,
          -830.5,
          -1333.1,
          -553.8,
      ]
      np.testing.assert_array_almost_equal(
          grad[0], grad_expected, decimal=1
      )
  
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 9 for calling the TestKerasRegressor obj's underlying member method code with example usage: obj.test_loss_gradient() without return types