CAAnimationGroup顺序执行animation

    CABasicAnimation *animation31 =[CABasicAnimation

                                    animationWithKeyPath: @"position.x" ];

    [animation31 setToValue:[NSNumber numberWithFloat:470]]; 

    animation31.cumulative=YES;

    animation31.duration = .1;

    [animation31 setFillMode:kCAFillModeForwards];  

    animation31.timingFunction = [CAMediaTimingFunction functionWithName: kCAMediaTimingFunctionEaseIn];

    [animation31 setRemovedOnCompletion:NO];  

    

    CAAnimationGroup *group = [CAAnimationGroup animation];

    group.animations = [NSArray arrayWithObjects:animation31, nil];

    group.duration = .1;

    group.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

    group.autoreverses = YES;

    group.repeatCount = 2;

    

    [garbagebutton.layer addAnimation:group forKey:nil];