in src/main/java/com/spotify/futures/FuturesExtra.java [557:564]
public static <Z, A, B, C, D> ListenableFuture<Z> syncTransform4(
ListenableFuture<A> a,
ListenableFuture<B> b,
ListenableFuture<C> c,
ListenableFuture<D> d,
final Function4<Z, ? super A, ? super B, ? super C, ? super D> function) {
return syncTransform4(a, b, c, d, function, MoreExecutors.directExecutor());
}