Set<FGEdge> getInEdges(FGController controller, FGVertex vertex) {

		Set<FGEdge> edges = new HashSet<>();
		FGData functionGraphData = controller.getFunctionGraphData();
		FunctionGraph functionGraph = functionGraphData.getFunctionGraph();
		Graph<FGVertex, FGEdge> graph = functionGraph;
		Collection<FGEdge> inEdges = graph.getInEdges(vertex);
		if (inEdges == null) {
			return null;
		}

		edges.addAll(inEdges);
		return edges;
	}
Finds an existing vertex represented by this info.  Returns null if no vertex exists to 
match this info (this can happen if the code block structure has changed).

@param controller The controller used for the current function graph
@return an existing vertex represented by this info.  Returns null if no vertex exists to 
        match this info
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/graph/vertex/VertexInfo.java