on (updatefn, errorfn, cancelfn) {
		if (this[_done]) {
			throw new Error("Cannot cascade from cancelled");
		}
		return new Reactor(updatefn, errorfn, cancelfn).attach(this);
	}
// Returns new reactor as child of this
Returns new reactor as child of this
Returns new reactor as child of this
on (updatefn, errorfn, cancelfn) {
		if (this[_done]) {
			throw new Error("Cannot cascade from cancelled");
		}
		return new Reactor(updatefn, errorfn, cancelfn).attach(this);
	}
on ( updatefn , errorfn , cancelfn ) { if ( this [ _done ] ) { throw new Error ( "Cannot cascade from cancelled" ) ; } return new Reactor ( updatefn , errorfn , cancelfn ) . attach ( this ) ; }
Returns new reactor as child of this
Returns new reactor as child of this