code: def convert_country_to_iso_code(
      df: pd.DataFrame, country_column: str
  ) -> pd.DataFrame:
      if (
          df[country_column]
          .isin(CountrySearchKeyDetector.COUNTRIES.values())
          .all()
      ):
          return df
  
      df[country_column] = (
          df[country_column]
          .astype("string")
          .str.upper()
          .map(CountrySearchKeyDetector.COUNTRIES)
          .fillna(df[country_column])
      )
  
      return df
  
file_path: upgini/src/upgini/utils/country_utils.py
imports: import pandas
  from pandas.api.types import is_string_dtype
  from upgini.utils.base_search_key_detector import BaseSearchKeyDetector
label_desc: Use image node_id 3 for calling the CountrySearchKeyDetector obj's underlying member method code with example usage: obj.convert_country_to_iso_code(df, country_column) and returns: df, df