up-modify-group-flag 这句经过测试,作用也不太理解
注解上说:Modify the ctrl group flag for units in a search group.
• Modify the ctrl group flag for units in a search group. You must manage the group flag carefully in order to avoid unexpected situations. Please remove the group flag before modifying a flagged search group. You can find units from a flagged search group using object-data-group-flag, which is set to the group id.