@Override
	protected FGVertex getRoot(VisualGraph<FGVertex, FGEdge> g) {
		if (graph instanceof FunctionGraph fg) {
			return fg.getRootVertex();
		}
		return null;
	}
Adapts the {@link AbstractFlowChartLayout} to work for {@link FunctionGraph}s.
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/graph/layout/flowchart/FGFlowChartLayout.java