如何验证元素是否包含任何文本？

I often need to wait for an AJAX call to add text to an element on my pages after they finish loading. I understand how to use WebDriverWait to wait for specific text to be present in the element, but I don't see how to wait until there is ANY text present. I'm trying to avoid a while loop that keeps checking the element's text isn't I often need to wait for an AJAX call to add te