code: def test_add_scalar(self):
      self.check_array_scalar_op("add")
  
imports: import unittest
  import pytest
  from cupy_backends.cuda import stream
  import cupy
  from cupy import _core
  from cupy import testing
label_desc: Use image node_id 3 for calling the TestElementwiseKernel obj's underlying member method code with example usage: obj.test_add_scalar() without return types