code: def test_multi_gpu(self):
      with cuda.Device(0):
          a = cupy.zeros((10,))
          scan(a)
      with cuda.Device(1):
          a = cupy.zeros((10,))
          scan(a)
  
file_path: cupy/tests/cupy_tests/core_tests/test_scan.py
imports: import unittest
  import cupy
  from cupy import cuda
  from cupy._core._routines_math import _scan_for_test
  from cupy import testing
label_desc: Use image node_id 3 for calling the TestScan obj's underlying member method code with example usage: obj.test_multi_gpu() without return types