old_contents: import unittest
  
  import numpy
  
  import chainer.functions as F
  from chainer import testing
  
  
  def make_data(dtype, shape):
      x = numpy.random.uniform(0.1, 5, shape).astype(dtype)
      gy = numpy.random.uniform(-1, 1, shape).astype(dtype)
      return x, gy
  
  
  #
  # sqrt
  
  @testing.math_function_test(F.Sqrt(), make_data=make_data)
  class TestSqrt(unittest.TestCase):
      pass
  
  
  #
  # rsqrt
  
  def rsqrt(x, dtype=numpy.float32):
      return numpy.reciprocal(numpy.sqrt(x, dtype=dtype))
  
  
  # TODO(takagi) Fix test of rsqrt not to use this decorator.
  @testing.math_function_test(F.rsqrt, func_expected=rsqrt, make_data=make_data)
  class TestRsqrt(unittest.TestCase):
      pass
  
  
  testing.run_module(__name__, __file__)
  
new_contents: import unittest
  
  import numpy
  
  import chainer.functions as F
  from chainer import testing
  
  
  #
  # sqrt
  
  def make_data(dtype, shape):
      x = numpy.random.uniform(0.1, 5, shape).astype(dtype)
      gy = numpy.random.uniform(-1, 1, shape).astype(dtype)
      return x, gy
  
  
  @testing.math_function_test(F.Sqrt(), make_data=make_data)
  class TestSqrt(unittest.TestCase):
      pass
  
  
  #
  # rsqrt
  
  def rsqrt(x):
      return numpy.reciprocal(numpy.sqrt(x))
  
  
  class TestRsqrt(unittest.TestCase):
  
      def test_rsqrt(self):
          x = numpy.random.uniform(0.1, 5, (3, 2)).astype(numpy.float32)
          testing.assert_allclose(F.rsqrt(x).data, rsqrt(x))
  
  
  testing.run_module(__name__, __file__)
  
subject: Simplify test of rsqrt function.