private void doClearSystemClipboard(Clipboard systemClipboard) {
		// for some reason setting the contents to null for the system clipboard causes a
		// NullPointerException, so just set it with an empty transferable.
		ProgramTreeTransferable dummyContents = new ProgramTreeTransferable(new ProgramNode[0]);
		systemClipboard.setContents(dummyContents, (clipboard, contents) -> {
			// a dummy implementation that will not prevent this plugin from being
			// reclaimed when it is disposed
		});
	}
Clear the system clipboard if there is tree transferable data on it.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramTreeActionManager.java