filterOptions (options, search, label, customLabel) {
      return search
        ? options
          .filter((option) => includes(customLabel(option, label), search))
          .sort((a, b) => {
            if (typeof this.filteringSortFunc === 'function') {
              return this.filteringSortFunc(a, b)
            }
            return customLabel(a, label).length - customLabel(b, label).length
          })
        : options
    }
Filters and sorts the options ready for selection
@param {Array} options
@param {String} search
@param {String} label
@param {Function} customLabel
@returns {Array}