### Question:
LikeService { public LikeService() { } LikeService(); Long like(String userId, String entityId); Long dislike(String userId, String entityId); int getLikeStatus(String userId, String entityId); Long getLikeCount(String entityId);  }### Answer:
@Test public void testLikeService() { LikeService likeService = new LikeService(); String entityId = "user1"; assertEquals(0, likeService.getLikeCount(entityId)); likeService.like("user2", entityId); likeService.like("user3", entityId); likeService.dislike("user4", entityId); assertEquals(2, likeService.getLikeCount(entityId)); assertEquals(1, likeService.getLikeStatus("user2", entityId)); assertEquals(-1, likeService.getLikeStatus("user4", entityId)); }