code: def test_donot_drop_nonevalues(self):
      # GH21356
      data = [
          {
              "info": None,
              "author_name": {
                  "first": "Smith",
                  "last_name": "Appleseed",
              },
          },
          {
              "info": {
                  "created_at": "11/08/1993",
                  "last_updated": "26/05/2012",
              },
              "author_name": {"first": "Jane", "last_name": "Doe"},
          },
      ]
      result = nested_to_record(data)
      expected = [
          {
              "info": None,
              "author_name.first": "Smith",
              "author_name.last_name": "Appleseed",
          },
          {
              "author_name.first": "Jane",
              "author_name.last_name": "Doe",
              "info.created_at": "11/08/1993",
              "info.last_updated": "26/05/2012",
          },
      ]
  
      assert result == expected
  
imports: import json
  import numpy
  import pytest
  from pandas import DataFrame, Index, Series, json_normalize
  import pandas._testing
  from pandas.io.json._normalize import nested_to_record
label_desc: Use image node_id 9 for calling the TestNestedToRecord obj's underlying member method code with example usage: obj.test_donot_drop_nonevalues() without return types