code: def _rand(self):
      return np.random.uniform(-1, 1, (2, 3)).astype(np.float32)
  
imports: import unittest
  import mock
  import numpy
  import pytest
  import chainer
  from chainer.backends import cuda
  from chainer import testing
  from chainer.testing import attr
  import chainerx
label_desc: Use image node_id 1 for calling the TestBackwardTypeCheck obj's underlying member method code with example usage: obj._rand() and returns: np