code: def test_relu(self):
      Xpos = np.ones((5, 5)).astype(np.float32) - 0.5
      Xneg = np.ones((5, 5)).astype(np.float32) - 1.5
  
      workspace.FeedBlob("xpos", Xpos)
      workspace.FeedBlob("xneg", Xneg)
      model = ModelHelper(name="test_model")
      brew.relu(model, "xpos", "out_xpos", use_cudnn=True)
      brew.relu(model, "xneg", "out_xneg", use_cudnn=True)
      model.Validate()
      workspace.RunNetOnce(model.param_init_net)
      workspace.RunNetOnce(model.net)
  
      pos = workspace.FetchBlob("out_xpos")
      self.assertAlmostEqual(pos.mean(), 0.5)
      neg = workspace.FetchBlob("out_xneg")
      self.assertAlmostEqual(neg.mean(), 0)
  
imports: from caffe2.python import brew, core, scope, workspace
  from caffe2.python.modeling.parameter_info import ParameterTags
  from caffe2.python.model_helper import ModelHelper
  from caffe2.python.cnn import CNNModelHelper
  import unittest
  import numpy
label_desc: Use image node_id 1 for calling the BrewGPUTest obj's underlying member method code with example usage: obj.test_relu() without return types