import { animate , AnimationTriggerMetadata , state , style , transition , trigger } from '@angular/animations' ; const timing = 250 ; export const visible = trigger ( 'visible' , [ state ( 'in' , style ( { opacity : 1 } ) ) , transition ( 'void => *' , [ style ( { opacity : 0 } ) , animate ( timing ) ] ) , transition ( '* => void' , [ animate ( timing , style ( { opacity : 0 } ) ) ] ) ] ) ;