code: def test_default_init(self):
      default_dtype = os.environ.get("CHAINER_DTYPE", "float32")
      array = self._generate_array(numpy)
      self.assertEqual(default_dtype, array.dtype)
  
imports: import os
  import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import initializers
  from chainer import testing
  from chainer.testing import attr
  import chainerx
label_desc: Use image node_id 2 for calling the TestGenerateArray obj's underlying member method code with example usage: obj.test_default_init() without return types