code: def p_mixin_guard_cond_list_aux(self, p):
          
          p[1].append(p[2])
          p[1].append(p[3])
          p[0] = p[1]
docs: mixin_guard_cond_list    : mixin_guard_cond_list t_comma mixin_guard_cond
                                       | mixin_guard_cond_list less_and mixin_guard_cond