<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _adj_for_assc(self):
 """Print only GO IDs from associations and their ancestors."""

        if self.gene2gos:
            gos_assoc = set(get_b2aset(self.gene2gos).keys())
            if 'item_marks' not in self.kws:
                self.kws['item_marks'] = {go:'>' for go in gos_assoc}
            if 'include_only' not in self.kws:
                gosubdag = GoSubDag(gos_assoc, self.gosubdag.go2obj,
                                    self.gosubdag.relationships)
                self.kws['include_only'] = gosubdag.go2obj