code: def test_scan_out(self, dtype):
      element_num = 10000
  
      if dtype in {cupy.int8, cupy.uint8, cupy.float16}:
          element_num = 100
  
      a = cupy.ones((element_num,), dtype=dtype)
      b = cupy.zeros_like(a)
      scan(a, b)
      expect = cupy.arange(start=1, stop=element_num + 1).astype(dtype)
  
      testing.assert_array_equal(b, expect)
  
      scan(a, a)
      testing.assert_array_equal(a, expect)
  
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 4 for calling the TestScan obj's underlying member method code with example usage: obj.test_scan_out(dtype) without return types