Function answers_by_itself 

pub fn answers_by_itself(verb: Verb, selector: &str, value: &str) -> bool

Whether the browser’s own default action of verb on the element selector names changes it — typing enters text into a control that takes typed text, choosing selects an option the <select> offers — so the verb is answered whether or not the page listens: the value it entered is on the page, and the control’s validity with it. A click, a press, a submit and a hover answer only through a listener (a checkbox’s click is answered by its toggle, where the click is decided).