text: """
  Copyright 2020 The OneFlow Authors. All rights reserved.
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  """
  
  import os
  import unittest
  
  import numpy as np
  
  import oneflow.compatible.single_client.unittest
  from oneflow.compatible import single_client as flow
  from oneflow.compatible.single_client import typing as tp
  
  
  @flow.unittest.skip_unless_1n2d()
  class TestInterfaceOpReadAndWrite(flow.unittest.TestCase):
      @unittest.skipIf(os.getenv("ONEFLOW_TEST_CPU_ONLY"), "only test cpu cases")
      def test(test_case):
          flow.config.gpu_device_num(2)
  
          @flow.global_function()
          def add() -> tp.Numpy:
              with flow.scope.placement("gpu", "0:0-1"):
                  x = flow.get_variable(
                      name="x",
                      shape=(2, 3),
                      initializer=flow.random_uniform_initializer(),
                  )
                  y = flow.get_variable(
                      name="y",
                      shape=(2, 3),
                      initializer=flow.random_uniform_initializer(),
                  )
                  return flow.math.add_n([x, y])
  
          flow.train.CheckPoint().init()
          if flow.eager_execution_enabled():
              add()
          x_value = np.random.random((2, 3)).astype(np.float32)
          y_value = np.random.random((2, 3)).astype(np.float32)
          flow.experimental.set_interface_blob_value("x", x_value)
          flow.experimental.set_interface_blob_value("y", y_value)
          test_case.assertTrue(
              np.array_equal(x_value, flow.experimental.get_interface_blob_value("x"))
          )
          test_case.assertTrue(
              np.array_equal(y_value, flow.experimental.get_interface_blob_value("y"))
          )
          test_case.assertTrue(np.array_equal(add(), x_value + y_value))
  
  
  if __name__ == "__main__":
      unittest.main()
  