code: def __str__(self):
      return "TestObject"
  
imports: from __future__ import annotations
  import datetime
  import unittest
  from decimal import Decimal
  import numpy
  import pandas
  import pyarrow
  from parameterized import parameterized
  from streamlit.elements.lib.column_config_utils import _EDITING_COMPATIBILITY_MAPPING, INDEX_IDENTIFIER, ColumnConfigMapping, ColumnConfigMappingInput, ColumnDataKind, _convert_column_config_to_json, _determine_data_kind, _determine_data_kind_via_arrow, _determine_data_kind_via_inferred_type, _determine_data_kind_via_pandas_dtype, apply_data_specific_configs, determine_dataframe_schema, is_type_compatible, process_config_mapping, update_column_config
  from streamlit.elements.lib.column_types import ColumnConfig
  from streamlit.errors import StreamlitAPIException
  from streamlit.type_util import DataFormat
label_desc: Use image node_id 1 for calling the TestObject obj's underlying member method code with example usage: obj.__str__() and returns: str