code: def generate_inputs(self):
      shape = self.shape
      (a,) = super().generate_inputs()
      indices = numpy.asarray([i for i in numpy.ndindex(shape)])
      numpy.random.shuffle(indices)
      if len(indices) == 0:
          n_nans = 0
      else:
          n_nans = numpy.random.randint(len(indices))
      if n_nans == 0:
          return (a,)
      nan_indices = indices[:n_nans]
      for i in nan_indices:
          a[tuple(i)] = numpy.nan
      return (a,)
  
imports: import chainer
  import numpy
  import pytest
  import chainerx
  import chainerx.testing
  from chainerx_tests import array_utils
  from chainerx_tests import math_utils
  from chainerx_tests import op_utils
label_desc: Use image node_id 2 for calling the TestNansum obj's underlying member method code with example usage: obj.generate_inputs() and returns: a, a