old_contents: import unittest
  
  import numpy
  
  import chainer
  from chainer import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
  
  
  if cuda.available:
      cuda.init()
  
  
  class TestDropout(unittest.TestCase):
  
      def setUp(self):
          self.x = numpy.random.uniform(-1, 1, (2, 3)).astype(numpy.float32)
          self.gy = numpy.random.uniform(-1, 1, (2, 3)).astype(numpy.float32)
  
      def check_type_forward(self, x_data):
          x = chainer.Variable(x_data)
          functions.dropout(x)
  
      def test_type_forward_cpu(self):
          self.check_type_forward(self.x)
  
      @attr.gpu
      def test_type_forward_gpu(self):
          self.check_type_forward(cuda.to_gpu(self.x))
  
      def check_type_backward(self, x_data, gy_data):
          x = chainer.Variable(x_data)
          y = functions.dropout(x)
          y.grad = gy_data
          y.backward()
  
      def test_type_backward_cpu(self):
          self.check_type_backward(self.x, self.gy)
  
      def test_type_backward_gpu(self):
          self.check_type_backward(
              cuda.to_gpu(self.x),
              cuda.to_gpu(self.gy))
  
  
  testing.run_module(__name__, __file__)
  
new_contents: import unittest
  
  import numpy
  
  import chainer
  from chainer import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
  
  
  if cuda.available:
      cuda.init()
  
  
  class TestDropout(unittest.TestCase):
  
      def setUp(self):
          self.x = numpy.random.uniform(-1, 1, (2, 3)).astype(numpy.float32)
          self.gy = numpy.random.uniform(-1, 1, (2, 3)).astype(numpy.float32)
  
      def check_type_forward(self, x_data):
          x = chainer.Variable(x_data)
          functions.dropout(x)
  
      def test_type_forward_cpu(self):
          self.check_type_forward(self.x)
  
      @attr.gpu
      def test_type_forward_gpu(self):
          self.check_type_forward(cuda.to_gpu(self.x))
  
      def check_type_backward(self, x_data, gy_data):
          x = chainer.Variable(x_data)
          y = functions.dropout(x)
          y.grad = gy_data
          y.backward()
  
      def test_type_backward_cpu(self):
          self.check_type_backward(self.x, self.gy)
  
      @attr.gpu
      def test_type_backward_gpu(self):
          self.check_type_backward(
              cuda.to_gpu(self.x),
              cuda.to_gpu(self.gy))
  
  
  testing.run_module(__name__, __file__)
  
subject: Add attr.gpu decorator