How to execute GM_addStyle() command with 5 seconds delay?

[Ben Stover]

Assume I want to execute the following statement with a delay of 5 seconds (to allow loading the web page at first completely):

GM_addStyle("#aaa { display: none !important; }");

then the following GM code does NOT work:

window.setTimeout(function() { GM_addStyle("#aaa { display: none !important; }");} ,5000);

Is there another way to deleay execution?