public TickBoxState getState(final ExplorerNode item) {
        final TickBoxState state = stateMap.get(item);
        if (state == null) {
            return TickBoxState.UNTICK;
        }
        return state;
    }
Get the set of selected items.

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