@Override
    public Location getRootLocation() {
        return location;
    }
Convenience constructor, using a default for the rootLocation and the
alignmentInLevel.
<p>
see
{@link #DefaultConfiguration(
double,
double,
stroom.widget.htree.client.treelayout.Configuration.Location,
stroom.widget.htree.client.treelayout.Configuration.AlignmentInLevel)}
stroom-core-client-widget/src/main/java/stroom/widget/htree/client/treelayout/util/DefaultConfiguration.java