code: def test_estimate_integral(self):
      self.ig = gradient_maps.IntegratedGradients()
  
      result = self.ig.estimate_integral(np.array([[0], [1], [2]]))
      target = np.array([1])
      np.testing.assert_almost_equal(result, target)
  
      result = self.ig.estimate_integral(
          np.array([[0, 0], [0, 0], [0, 1]])
      )
      target = np.array([0, 0.25])
      np.testing.assert_almost_equal(result, target)
  
file_path: lit/lit_nlp/components/gradient_maps_test.py
imports: from absl.testing import absltest
  from absl.testing import parameterized
  from lit_nlp.api import dataset
  from lit_nlp.components import gradient_maps
  from lit_nlp.lib import testing_utils
  import numpy
label_desc: Use image node_id 4 for calling the GradientMapsTest obj's underlying member method code with example usage: obj.test_estimate_integral() without return types