### Question:
MapUtil { public static <K, V> MapPlain<K, V> build() { return new MapPlain<>(); }  static MapPlain<K, V> build(); static MapPlain<K, V> build(int cap); static Map<String, Object> toMap(Object o, Map<String, String> map, String... ignoreProperties); static Map<String, Object> toMap(Object o, String... ignoreProperties); static void toObject(Map<String, Object> source, Object target, String... ignoreProperties); static List<Map<String, Object>> mapConvertToList(Map<K, V> map); static List<Map<String, Object>> mapConvertToList(Map<K, V> map, Object defaultValue);  }### Answer:
@Test public void testMapPlainPut() { Map<String, Object> map = MapUtil.<String, Object>build(1).put("name", "name").get(); assertEquals(map.get("name"), "name"); }
@Test public void testMapPlainPutAll() { Map<String, Object> mapAll = new HashMap<>(); mapAll.put("name", "name"); mapAll.put("age", 25); Map<String, Object> map = MapUtil.<String, Object>build().putAll(mapAll).get(); assertEquals(map.get("name"), "name"); assertEquals(map.get("age"), 25); }
@Test public void testMapPlainPutAllEmpty() { Map<String, Object> mapAll = new HashMap<>(); Map<String, Object> map = MapUtil.<String, Object>build().putAll(mapAll).get(); assertEquals(map.size(), 0); }