### Question:
EntityCollection extends BaseObject { public T first(Object... paramValues) { List<T> list = where(createFilter(paramValues)); if (list.isEmpty()) { return null; } return list.get(0); }  T add(T item); T remove(T item); T findById(Serializable id); List<T> all(); T first(Object... paramValues); T one(Object... paramValues); List<T> where(Filter filter); List<T> where(Object... paramValues); long count(Filter filter); void persist();  }### Answer:
@Test public void shouldSearchAndReturnFirst() { assertEquals(model.collection("children").first("children.column1", "testChildColumn1"), child2); }
@Test public void shouldSearchAndReturnNullIfNoElementExistOnFirst() { assertNull(model.collection("children").first("children.column1", "unknown")); }