private void removeDescendants(final ExplorerNode item) {
        modifyState(item, TickBoxState.UNTICK);
        Set<ExplorerNode> set = descendants.get(item);
        if (set != null) {
            for (final ExplorerNode descendant : set) {
                removeDescendants(descendant);
            }
            descendants.remove(item);
        }
    }
Get the set of selected items.

@return the set of selected items
stroom-core-client/src/main/java/stroom/explorer/client/presenter/TickBoxSelectionModel.java