CollectionUtil { public static <T> List<String> toStringList(final Collection<T> collection) { final List<String> returnList = new ArrayList<>(collection.size()); collection.forEach(o -> returnList.add(o.toString())); return returnList; }  static int clear(final Collection collection); static List<String> toStringList(final Collection<T> collection); static String smartJoin(final Collection<T> collection,
        final Generator<T, String> stringGenerator, final String joiner); @SafeVarargs static C arrayToCollection(
        final Supplier<C> creator, final T... array); @Deprecated static Collection<String> toStringCollection(final String stringList); static String join(final Collection<T> collection, String joiner); static boolean containsIgnoreCase(final Collection<? extends String> collection,
        final String string);  }
@Test void toStringList() { final Collection<Object> objects = Arrays.asList(3, 8f, true); final Collection<?> converted = CollectionUtil.toStringList(objects); converted.forEach(object -> Assertions.assertTrue(object instanceof String)); }