@Override
	protected Set<AttributedVertex> getVertices(AddressSetView selection) {
		if (graphType != CONTROL_FLOW_GRAPH) {
			return null;
		}
		Set<AttributedVertex> vertices = new HashSet<>();
		List<PcodeBlockBasic> blocks = hfunction.getBasicBlocks();
		for (PcodeBlockBasic block : blocks) {
			Address start = block.getStart();
			Address stop = block.getStop();
			if (selection.intersects(start, stop)) {
				String id = Integer.toString(block.getIndex());
				AttributedVertex vertex = graphDisplay.getGraph().getVertex(id);
				if (vertex != null) {
					vertices.add(vertex);
				}
			}
		}
		return vertices;
	}
Listener for when an AST graph's nodes are selected.
Ghidra/Features/Decompiler/src/main/java/ghidra/app/plugin/core/decompile/actions/PCodeCfgDisplayListener.java