guava中Collection的transform遇到需要跳过的处理

 1 Iterable<Rds> iterable = Optional.presentInstances(Lists.transform(serviceInstances, new Function<ServiceInstance, Optional<Rds>>() {
 2     @Nullable
 3     @Override
 4     public Optional<Rds> apply(@Nullable ServiceInstance input) {
 5         if (remove) {
 6             return Optional.absent();
 7         }
 8         return Optional.of(buildRds(input));
 9     }
10 }));