private Icon getIcon(AttributedVertex vertex) {

		// WARNING: very important to not use map's computeIfAbsent() method
		// because the map is synchronized and the createIcon() method will
		// attempt to acquire the AWT lock. That combination will cause a deadlock
		// if computeIfAbsent() is used and this method is called from non-swing thread.
		Icon icon = iconCache.get(vertex);
		if (icon == null) {
			icon = createIcon(vertex);
			iconCache.put(vertex, icon);
		}
		return icon;
	}
Handles the rendering of graphs for the {@link DefaultGraphDisplay}
Ghidra/Features/GraphServices/src/main/java/ghidra/graph/visualization/DefaultGraphRenderer.java