code: def setUp(self):
      super().setUp()
      self.bg = random._bit_generator.MRG32k3a
  
imports: import unittest
  import pytest
  import numpy
  import cupy
  from cupy import random
  from cupy import testing
label_desc: Use image node_id 1 for calling the TestBitGeneratorMRG32k3a obj's underlying member method code with example usage: obj.setUp() without return types