I need to count webElements on page. Initially, it opens only few elements, but when you scroll down - new elements appear. You can't use ExpectedConditions.numberOfElementsToBeLessThan() because it's not known how many elements will be on page.

To solve the problem i need just make selenium wait for few seconds until new elements appear in DOM. But it's not allowed to use thread.sleep.
So, how can i fix that?