private void addCloseAction() {
		DockingAction closeAction = new DockingAction("Close Tool", ToolConstants.TOOL_OWNER) {
			@Override
			public void actionPerformed(ActionContext context) {
				close();
			}
		};
		closeAction.setHelpLocation(
			new HelpLocation(ToolConstants.TOOL_HELP_TOPIC, closeAction.getName()));
		closeAction.setEnabled(true);

		closeAction.setMenuBarData(
			new MenuData(new String[] { ToolConstants.MENU_FILE, "Close Tool" }, null, "Window_A"));

		addAction(closeAction);
	}
We need to do this here, since our parent constructor calls methods on us that need the 
extension manager.
@return the extension manager
Ghidra/Framework/Project/src/main/java/ghidra/framework/project/tool/GhidraTool.java