get text()
    {
        return this._element.textContent;
    }
Clients should never attach any event listeners to the |element|. Instead,
they should use the result of this method to attach listeners for bubbling events
or the |blurListener| parameter to register a "blur" event listener on the |element|
(since the "blur" event does not bubble.)

@param {Element} element
@param {function(Event)} blurListener