code: def setup(self, dtype):
      try:
          a_np = self.input.astype(dtype)
      except (ValueError, OverflowError):
          raise unittest.SkipTest(
              "invalid combination of data and dtype"
          )
  
      self.a_np = a_np.astype(numpy.float32)
  
imports: import unittest
  import chainer
  import numpy
  import chainerx.testing
  from chainerx_tests import op_utils
label_desc: Use image node_id 1 for calling the TestNanArgmax obj's underlying member method code with example usage: obj.setup(dtype) without return types