code: public static <T> CompletableFuture<T> toCompletableFuture(ApiFuture<T> apiFuture) {
          return Java8FutureUtils.createCompletableFuture(ApiFutureUtils.createValueSourceFuture(apiFuture));
      }
docs: Converts  {@link com.google.api.core.ApiFuture} to {@link java.util.concurrent.CompletableFuture}.