code: def testMergeNestedOptions(self):
      options1, options2 = _NestedTestOptions(), _NestedTestOptions()
      merged_options = options.merge_options(options1, options2)
      self.assertEqual(merged_options.opts, None)
      options1.opts = _TestOptions()
      merged_options = options.merge_options(options1, options2)
      self.assertEqual(merged_options.opts, _TestOptions())
      options2.opts = _TestOptions()
      merged_options = options.merge_options(options1, options2)
      self.assertEqual(merged_options.opts, _TestOptions())
      options1.opts.x = 0
      options2.opts.y = 0.0
      merged_options = options.merge_options(options1, options2)
      self.assertEqual(merged_options.opts.x, 0)
      self.assertEqual(merged_options.opts.y, 0.0)
  
imports: from absl.testing import parameterized
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.util import options
  from tensorflow.python.framework import combinations
  from tensorflow.python.platform import test
label_desc: Use image node_id 4 for calling the OptionsTest obj's underlying member method code with example usage: obj.testMergeNestedOptions() without return types