code: def test_covariance_cpu(self):
      self.check_covariance(False)
  
imports: import functools
  import itertools
  import operator
  import numpy
  from chainer import distributions
  from chainer import testing
  from chainer.testing import array
  from chainer.testing import attr
  from chainer import utils
label_desc: Use image node_id 6 for calling the TestIndependentNormal obj's underlying member method code with example usage: obj.test_covariance_cpu() without return types