text: class MouseWheel {
      constructor (runtime) {
          /**
           * Reference to the owning Runtime.
           * @type{!Runtime}
           */
          this.runtime = runtime;
      }
  
      /**
       * Mouse wheel DOM event handler.
       * @param  {object} data Data from DOM event.
       */
      postData (data) {
          const matchFields = {};
          if (data.deltaY < 0) {
              matchFields.KEY_OPTION = 'up arrow';
          } else if (data.deltaY > 0) {
              matchFields.KEY_OPTION = 'down arrow';
          } else {
              return;
          }
  
          this.runtime.startHats('event_whenkeypressed', matchFields);
      }
  }
  
  module.exports = MouseWheel;
  