private void updatePopupMenu(boolean isSignatureAction) {
		if (isSignatureAction) {
			setPopupMenuData(new MenuData(new String[] { FunctionPlugin.FUNCTION_MENU_PULLRIGHT,
				"Delete VarArgs" }, null, FunctionPlugin.FUNCTION_MENU_SUBGROUP));
		}
		else {
			setPopupMenuData(new MenuData(new String[] { FunctionPlugin.VARIABLE_MENU_PULLRIGHT,
				"Delete VarArgs" }, null, FunctionPlugin.VARIABLE_MENU_SUBGROUP));
		}
	}
Action that changes a Function so that it has VarArgs (a variable argument list).
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/function/DeleteVarArgsAction.java