### Question:
FollowingsMapper { public Followings findFollowingsByUsername(String username) { return this.jdbcTemplate.query("SELECT t.username, f.followee AS tweeter FROM tweeters AS t INNER JOIN followings AS f ON t.username = f.follower WHERE t.username = ? ORDER BY f.created_at DESC", followingsResultSetExtractor, username); } FollowingsMapper(JdbcTemplate jdbcTemplate); Followings findFollowingsByUsername(String username); Followings findFollowersByUsername(String username);  }### Answer:
@Test void findFollowingsByUsername() { final Followings followings = this.followingsMapper.findFollowingsByUsername("foo"); assertThat(followings.getUsername()).isEqualTo("foo"); assertThat(followings.getTweeters()).containsExactly(new Tweeter("foo4"), new Tweeter("foo3"), new Tweeter("foo2")); }