code: def test_activation_forward(self):
      cudnn.activation_forward(self.x, self.mode)
  
imports: import sys
  import numpy
  import pytest
  import cupy
  import cupy.cuda.cudnn
  from cupy import testing
label_desc: Use image node_id 2 for calling the TestCudnnActivation obj's underlying member method code with example usage: obj.test_activation_forward() without return types