public void setItemOpen(final ExplorerNode item, final boolean open) {
        if (item != null) {
            if (open != openItems.isOpen(item.getUniqueKey())) {
                refresh(openItems.toggleOpenState(item.getUniqueKey()));
            }
        }
    }
For use when setting an initial value for the filter.
stroom-core-client/src/main/java/stroom/explorer/client/presenter/ExplorerTreeModel.java