@Override
	protected TestVisualGraph buildGraph() {

		TestVisualGraph g = new TestVisualGraph();

		AbstractTestVertex v1 = new LabelTestVertex("1");
		AbstractTestVertex v2 = new LabelTestVertex("2");
		AbstractTestVertex v3 = new LabelTestVertex("3");
		TextAreaTestVertex textAreaVertex = new TextAreaTestVertex("Text Area vertex...");
		TestEdge e1 = new TestEdge(v1, v2);
		TestEdge e2 = new TestEdge(v2, v3);
		TestEdge e3 = new TestEdge(v1, textAreaVertex);

		g.addVertex(v1);
		g.addVertex(v2);
		g.addVertex(v3);
		g.addVertex(textAreaVertex);
		g.addEdge(e1);
		g.addEdge(e2);
		g.addEdge(e3);

		return g;
	}
A version of the {@link AbstractVisualGraphTest} that creates a simple graph (this class 
may not be needed, but the hope is that more default state can be recorded here)
Ghidra/Framework/Graph/src/test.slow/java/ghidra/graph/viewer/AbstractSimpleVisualGraphTest.java