@Override
	public void processEvent(PluginEvent event) {
		if (event instanceof ProgramClosedPluginEvent) {
			Program program = ((ProgramClosedPluginEvent) event).getProgram();
			programClosed(program);
			return;
		}
	}
Plugin to find all possible references to the address at the
current cursor location.  A reference is some set of bytes that
when treated as an address would be the address of the current
cursor location.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/analysis/FindPossibleReferencesPlugin.java