private boolean currentGraphContainsEventAddress(DomainObjectChangedEvent ev) {
		FGData functionGraphData = controller.getFunctionGraphData();
		FunctionGraph graph = functionGraphData.getFunctionGraph();
		for (int i = 0; i < ev.numRecords(); i++) {
			Address address = getChangedAddress(ev.getChangeRecord(i));
			if (address != null && graph.getVertexForAddress(address) != null) {
				return true;
			}
		}
		return false;
	}
Returns true when something destructive has happened to the data upon which the graph has
created, like a memory block move.
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/FGProvider.java