code: def test_gradient(self, x, in_place, gc, dc):
      def f(inputs, outputs):
          outputs[0].reshape(inputs[0].shape)
          outputs[0].data[...] = inputs[0].data * 2
  
      def grad_f(inputs, outputs):
          # Ordering is [inputs, outputs, grad_outputs]
          grad_output = inputs[2]
  
          grad_input = outputs[0]
          grad_input.reshape(grad_output.shape)
          grad_input.data[...] = grad_output.data * 2
  
      op = CreatePythonOperator(
          f, ["x"], ["x" if in_place else "y"], grad_f=grad_f
      )
      self.assertGradientChecks(gc, op, [x], 0, [0])
      self.assertDeviceChecks(dc, op, [x], [0])
  
imports: from caffe2.python import core, workspace
  from caffe2.python.core import CreatePythonOperator
  import caffe2.python.hypothesis_test_util
  from hypothesis import given, settings
  import hypothesis.strategies
  import numpy
label_desc: Use image node_id 11 for calling the PythonOpTest obj's underlying member method code with example usage: obj.test_gradient(x, in_place, gc, dc) without return types