code: def test_charac():
      """Ensure non standard characters and spaces have been cleaned up."""
  
      df = pd.DataFrame(
          {
              r"Current accountbalance(in % of GDP)": range(5),
          }
      )
      df = df.clean_names(strip_underscores=True, case_type="lower")
  
      assert "current_accountbalance_in_%_of_gdp" in df.columns
  
file_path: pyjanitor/tests/functions/test_clean_names.py
imports: import pandas
  import pytest
  from janitor.errors import JanitorError
label_desc: Use image node_id 14 for calling a global function with example usage: test_charac() without return types