handleClick_(clickEvt) {
    var icon = /** @type {HTMLElement} */ (clickEvt.target);
    if (!(icon instanceof HTMLImageElement)) {
      return;
    }

    var callback =
        goog.dom.classlist.contains(icon, constants.CssClass.REMOVE) ?
        this.removeKeyCallback_ :
        this.exportKeyCallback_;
    var parentTR = this.getParentTableRow_(icon);
    var keyUid =
        goog.dom.getElementByClass(constants.CssClass.KEY_UID, parentTR)
            .textContent;
    callback(keyUid);
  }
Handles events when the user clicks on export/remove icons in the UI.
@param {!goog.events.Event} clickEvt The event generated by the user's
    click.
@private