private Set<AttributedVertex> getAllUpstreamVerticesFromSelected() {
		Set<AttributedVertex> upstream = new HashSet<>();
		Set<AttributedVertex> sources = getUnselectedSourceVerticesFromSelected();
		while (!sources.isEmpty()) {
			growSelection(sources);
			upstream.addAll(sources);
			sources = getUnselectedSourceVerticesFromSelected();
		}
		return upstream;
	}
Ungroup the selected vertices. If the focusedVertex is no longer in the graph, null it. This
will happen if the focusedVertex was the GroupVertex
Ghidra/Features/GraphServices/src/main/java/ghidra/graph/visualization/DefaultGraphDisplay.java