class BarBuilderNodeDescriptor implements BarBuilderDescriptor {

    static PeriodType getLowerBaseType(PeriodType type) {
        PeriodType retType = null;
        int idx = 0;
        while(idx < baseTypeSteps.size() && (retType == null || baseTypeSteps.get(idx).isLowerThan(type))) {
            retType = baseTypeSteps.get(idx++);
        }
        return retType;
    }

    public  BarBuilderNodeDescriptor();

}