code: def test_float8_e5m2fnuz_negative_zero(self):
      x = numpy_helper.float8e5m2_to_float32(0x80)  # -0
      to = helper.float32_to_float8e5m2(x, fn=True, uz=True)
      self.assertEqual(to, 0)
      back = numpy_helper.float8e4m3_to_float32(to, fn=True, uz=True)
      self.assertEqual(back, 0)
  
      x = numpy_helper.float8e5m2_to_float32(0x80)  # -0
      to = helper.float32_to_float8e5m2(
          x, fn=True, uz=True, saturate=False
      )
      self.assertEqual(to, 0)
      back = numpy_helper.float8e4m3_to_float32(to, fn=True, uz=True)
      self.assertEqual(back, 0)
  
imports: import unittest
  from typing import Any
  import numpy
  import parameterized
  import onnx
  from onnx import helper, numpy_helper
label_desc: Use image node_id 30 for calling the TestNumpyHelper obj's underlying member method code with example usage: obj.test_float8_e5m2fnuz_negative_zero() without return types