private void selectChildren(final ExplorerNode item) {
        final List<ExplorerNode> children = item.getChildren();
        if (children != null && children.size() > 0) {
            for (final ExplorerNode child : children) {
                modifyState(child, TickBoxState.TICK);
                addDescendants(getParent(child), child);
            }
        }
    }
Get the set of selected items.

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