修改群信息时，SessionViewController展示一条群提示消息：你更新了群名称。

xcode提示警告信息：

2020-04-09 14:42:04.537056+0800 GrootDev[81929:4510369] [TableView] Warning once only: UITableView was told to layout its visible cells and other contents without being in the view hierarchy (the table view or one of its superviews has not been added to a window). This may cause bugs by forcing views inside the table view to load and perform layout without accurate information (e.g. table view bounds, trait collection, layout margins, safe area insets, etc), and will also cause unnecessary performance overhead due to extra layout passes. Make a symbolic breakpoint at UITableViewAlertForLayoutOutsideViewHierarchy to catch this in the debugger and see what caused this to occur, so you can avoid this action altogether if possible, or defer it until the table view has been added to a window. Table view: <UITableView: 0x7fa51d83d400; frame = (0 0; 375 616); clipsToBounds = YES; autoresize = W+H; gestureRecognizers = <NSArray: 0x600003f36190>; layer = <CALayer: 0x6000031f0100>; contentOffset: {0, 273.5}; contentSize: {375, 889.33332824707031}; adjustedContentInset: {64, 0, 0, 0}; dataSource: <NIMSessionTableAdapter: 0x6000031f6740>>

通过UITableViewAlertForLayoutOutsideViewHierarchy断点定位出现问题的代码在NIMSessionLayoutImpl.m第241行：
{
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:addIndexPathes
withRowAnimation:UITableViewRowAnimationNone];
[self.tableView endUpdates];
[self.tableView scrollToRowAtIndexPath:addIndexPathes.lastObject
atScrollPosition:UITableViewScrollPositionTop
animated:NO];
}