@Override
	public FunctionGraph getVisualGraph() {
		return (FunctionGraph) getGraph();
	}
An abstract class that is the root for Function Graph layouts.  It changes the type of
the graph returned to {@link FunctionGraph} and defines a clone method that takes in a 
Function Graph.
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/graph/layout/AbstractFGLayout.java