private Set<Icon> getCoreIcons() {
			Set<Icon> loadedIcons = ResourceManager.getLoadedIcons();
			Set<Icon> filtered = new HashSet<>();
			for (Icon icon : loadedIcons) {
				if (isCoreIcon(icon)) {
					filtered.add(icon);
				}
			}
			return filtered;
		}
Returns all icons loaded by core Ghidra modules. For this use, we only want to use
icons that are part of a standard distribution because if they are exported, they may
not be available on import. Non-core icons can be used by picking them from the file
system.
@Return all icons loaded by core Ghidra modules
Ghidra/Framework/Docking/src/main/java/docking/options/editor/IconPropertyEditor.java