text: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  
  import math
  
  from caffe2.python import core
  from hypothesis import given, settings
  import caffe2.python.hypothesis_test_util as hu
  import caffe2.python.serialized_test.serialized_test_util as serial
  
  import numpy as np
  import unittest
  
  
  class TestErfOp(serial.SerializedTestCase):
      @given(
          X=hu.tensor(elements=hu.floats(min_value=-0.7, max_value=0.7)),
          **hu.gcs)
      @settings(deadline=1000)
      def test_erf(self, X, gc, dc):
          op = core.CreateOperator('Erf', ["X"], ["Y"])
          self.assertReferenceChecks(gc, op, [X], lambda x: (np.vectorize(math.erf)(X),))
          self.assertDeviceChecks(dc, op, [X], [0])
          self.assertGradientChecks(gc, op, [X], 0, [0])
  
  
  if __name__ == "__main__":
      unittest.main()
  