Get GO text from GOEA study.

def _get_study_txt(self, goid):
        """Get GO text from GOEA study."""
        if self.go2res is not None:
            res = self.go2res.get(goid, None)
            if res is not None:
                if self.study_items is not None:
                    return self._get_item_str(res)
                else:
                    return self.pltvars.fmtres.format(
                        study_count=res.study_count)