Couldn't import SystemEventsApplication

Try use this part part code

-(IBAction)goAway:(id)sender{
    SystemEventsApplication *systemEvents = [SBApplication applicationWithBundleIdentifier:@"com.apple.systemevents"];
    [systemEvents sleep];
}

But couldn't find from where import SystemEventsApplication and couldn't import SystemEvents.h

Find this solution here Programmatically put a Mac into sleep

Copyright Notice：Content Author:「shami13」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/17245703/couldnt-import-systemeventsapplication