@Override
	public void dispose() {
		super.dispose();

		if (panel != null) {
			panel.dispose();
			panel = null;
		}
		if (gotoHelper != null) {
			gotoHelper.dispose();
			gotoHelper = null;
		}
	}
A hover service to show tool tip text for hovering over a reference.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/hover/AbstractReferenceHover.java