code: function _getSelected(select) {
      const arr = [];
  
      _slice.call(select.options).map((el) => {
          if (el.selected) {
              arr.push(el.value);
          }
      });
  
      return arr;
  }
docs: Get the selected options from a select
  
  @private
  @param {HTMLElement} select
  @returns {Array} selected