def calculate_all_information_content(self) -> pd.Series:
        """
        Calculate the Information Content (IC) value of every class

        Sets the internal icmap cache and returns an array 

        Return
        ------
        Series
            a pandas Series indexed by class id and with IC as value
        """
        logging.info("Calculating all class ICs")
        df = self.assoc_df
        freqs = df.sum(axis=0)
        n_subjects, _ = df.shape
        ics = freqs.apply(lambda x: -math.log(x / n_subjects)/math.log(2))
        self.ics = ics
        logging.info("DONE calculating all class ICs")
        return ics