def _store_meta_info(self):
        """Update the meta dictionary with the current chunk of meta data details
        """
        # In the mass bank msp files, sometimes the precursor_mz is missing but we have the neutral mass and
        # the precursor_type (e.g. adduct) so we can calculate the precursor_mz
        if not self.meta_info['precursor_mz'] and self.meta_info['precursor_type'] and \
                self.compound_info['exact_mass']:
            self.meta_info['precursor_mz'] = get_precursor_mz(float(self.compound_info['exact_mass']),
                                                              self.meta_info['precursor_type'])

        if not self.meta_info['polarity']:
            # have to do special check for polarity (as sometimes gets missed)
            m = re.search('^\[.*\](\-|\+)', self.meta_info['precursor_type'], re.IGNORECASE)
            if m:
                polarity = m.group(1).strip()
                if polarity == '+':
                    self.meta_info['polarity'] = 'positive'
                elif polarity == '-':
                    self.meta_info['polarity'] = 'negative'

        if not self.meta_info['accession']:
            self.meta_info['accession'] = 'unknown accession'

        self.meta_info_all.append(
            (str(self.current_id_meta),) +
            tuple(self.meta_info.values()) +
            (str(self.current_id_origin), self.compound_info['inchikey_id'],)
        )
Update the meta dictionary with the current chunk of meta data details