Return a dataframe of validation results for the appropriate series vs the vector of validators.

        Args:
            table (pd.DataFrame): A dataframe on which to apply validation logic.
            failed_only (bool): If ``True``: return only the indexes that failed to validate.

def validate(self, table: pd.DataFrame, failed_only=False) -> pd.DataFrame:
        """Return a dataframe of validation results for the appropriate series vs the vector of validators.

        Args:
            table (pd.DataFrame): A dataframe on which to apply validation logic.
            failed_only (bool): If ``True``: return only the indexes that failed to validate.
        """
        raise NotImplementedError("This method must be defined for each subclass.")