public AxisLocation getDomainAxisLocation(int index) {
        AxisLocation result = null;
        if (index < this.domainAxisLocations.size()) {
            result = (AxisLocation) this.domainAxisLocations.get(index);
        }
        if (result == null) {
            result = AxisLocation.getOpposite(getDomainAxisLocation());
        }
        return result;