Read Gene Association File (GAF). Return data.

def get_taxid2asscs(self, taxids=None, **kws):
        """Read Gene Association File (GAF). Return data."""
        # WAS: get_annotations_taxid2dct
        taxid2asscs = cx.defaultdict(lambda: cx.defaultdict(lambda: cx.defaultdict(set)))
        options = AnnoOptions(self.evobj, **kws)
        for taxid in self._get_taxids(taxids):
            nts = self.taxid2asscs[taxid]
            assc = self.reduce_annotations(nts, options)
            taxid2asscs[taxid]['ID2GOs'] = self._get_dbid2goids(assc)
            taxid2asscs[taxid]['GO2IDs'] = self._get_goid2dbids(assc)
        return taxid2asscs