code: def check_savez(self, savez, dtype):
      a1 = testing.shaped_arange((2, 3, 4), dtype=dtype)
      a2 = testing.shaped_arange((3, 4, 5), dtype=dtype)
  
      sio = io.BytesIO()
      savez(sio, a1, a2)
      s = sio.getvalue()
      sio.close()
  
      sio = io.BytesIO(s)
      with cupy.load(sio) as d:
          b1 = d["arr_0"]
          b2 = d["arr_1"]
      sio.close()
  
      testing.assert_array_equal(a1, b1)
      testing.assert_array_equal(a2, b2)
  
file_path: cupy/tests/cupy_tests/io_tests/test_npz.py
imports: import io
  import pickle
  import unittest
  import cupy
  from cupy import testing
label_desc: Use image node_id 4 for calling the TestNpz obj's underlying member method code with example usage: obj.check_savez(savez, dtype) without return types