¿Cómo configurar diferentes vectores de dirección de gravedad para diferentes elementos de comportamiento de gravedad?

I have two UIViews.i want to set different gravitydirection vector for these two views for making **attraction**.and i am doing this by having two gravitybehavior but when i am adding these two to animator. it's not working as **attracting** to each other. also giving warning like :-Multiple gravity behavior per animator is undefined and may assert in the future. Below is the code i am using to make Attractiuon effect b/w two views. 

El comportamiento de la gravedad es hacer que la animation por gravedad. Y el animador sea un animador dynamic.

 UIGravityBehavior *gravityBehavior = [[UIGravityBehavior alloc] initWithItems:@[v1]]; CGVector vector = CGVectorMake(1.0, 1.0); [gravityBehavior setGravityDirection:vector]; UIGravityBehavior *gravityBehavior1 = [[UIGravityBehavior alloc] initWithItems:@[v2]]; CGVector vector1 = CGVectorMake(-1.0, -1.0); [gravityBehavior1 setGravityDirection:vector1]; gravityBehavior.magnitude=1000; self.animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view]; [self.animator addBehavior:gravityBehavior]; [self.animator addBehavior:gravityBehavior1]; 

¡Por favor ayuda! ¡¡Gracias por la ayuda!!