How to use the regionmask.core._geopandas._enumerate_duplicates function in regionmask

def separate_pacific(self):
        if self._separate_pacific is None:
            # need to fix the duplicates
            df = self._df.copy()
            df["V2"] = _enumerate_duplicates(df["V2"])

            self._separate_pacific = from_geopandas(
                df,
                names="V2",
                abbrevs="V3",
                name=self._name + "(separate Pacific regions)",
                source=self._source,
            )

        return self._separate_pacific