Return hdr line seen inside a GO Term box.

def str_fmthdr(self, goid, goobj):
        """Return hdr line seen inside a GO Term box."""
        # Shorten: Ex: GO:0007608 -> G0007608
        go_txt = goid.replace("GO:", "G")
        if 'mark_alt_id' in self.present and goid != goobj.id:
            go_txt += 'a'
        return go_txt