### Question:
EntityCollection extends BaseObject { public T one(Object... paramValues) { Filter filter = createFilter(paramValues); return createCollectionQuery(filter).getSingleResult(); }  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 shouldSearchAndReturnTheOnlyMatch() { assertEquals(model.collection("children").one("children.column1", "testChildColumn0", "children.column2", "testChildColumn2"), child1); }