code: def test_find_replace_null_raises_error(df):
      with pytest.raises(ValueError):
          df.find_replace(a={np.nan: 5})
  
file_path: pyjanitor/tests/functions/test_find_replace.py
imports: import numpy
  import pandas
  import pytest
label_desc: Use image node_id 3 for calling a global function with example usage: test_find_replace_null_raises_error(df) without return types