### Question:
LinkkiInMemoryContainer extends AbstractInMemoryContainer<T, Object, Item> implements Container.Hierarchical { @Override public boolean setChildrenAllowed(Object itemId, boolean areChildrenAllowed) throws UnsupportedOperationException { return false; }  @Override Collection<?> getContainerPropertyIds(); void setItems(Collection<? extends T> items); @Deprecated @Override boolean removeAllItems(); @Deprecated void addAllItems(Collection<T> items); @Override @CheckForNull Property<T> getContainerProperty(@CheckForNull Object itemId, Object propertyId); @Override @CheckForNull Class<?> getType(@CheckForNull Object propertyId); @Override @SuppressWarnings({ "unchecked" }) Collection<T> getChildren(Object itemId); Collection<T> getExistingChildren(T parent); boolean removeExistingChildren(T item); @CheckForNull @Override T getParent(Object itemId); @Override Collection<?> rootItemIds(); @Override boolean areChildrenAllowed(Object itemId); @Override boolean isRoot(Object itemId); @Override boolean hasChildren(Object itemId); @Override boolean setParent(Object itemId, Object newParentId); @Override boolean setChildrenAllowed(Object itemId, boolean areChildrenAllowed);  }### Answer:
@Test public void testSetChildrenAllowed() { LinkkiInMemoryContainer<TestItem> container = new LinkkiInMemoryContainer<>(); HierarchicalTestItem testItem = new HierarchicalTestItem(23); assertThat(container.setChildrenAllowed(testItem, true), is(false)); }