code: def serialized_dataframe(df):
      """Handles converting pandas objects to format that can handle equality comparisons"""
      return None if (df is None) else df.to_json()
  
file_path: dtale/tests/dtale/test_global_state.py
imports: import mock
  import pandas
  import pytest
  import dtale.global_state
  from dtale.views import build_dtypes_state
label_desc: Use image node_id 5 for calling a global function with example usage: serialized_dataframe(df) and returns: unknown