code: public static <F, T> List<T> transform(Collection<F> fromList,
              Function<? super F, ? extends T> function) {
          if (CollectionUtil.isEmpty(fromList)) {
              return Collections.emptyList();
          }
  
          List<T> ret = new ArrayList<T>(fromList.size());
          for (F f : fromList) {
              T t = function.apply(f);
              if (t == null) {
                  continue;
              }
              ret.add(t);
          }
  
          return ret;
      }
docs: List转换
  
  @param fromList
  @param function
  @return