code: function (input, list) {
      debug('chooseOneFilter(%s, %s)', input, JSON.stringify(list));
      if (input === true) return undefined;
      if (_.isString(input)) {
        if (_.isEmpty(input)) return undefined;
        var ilc = input.toLocaleLowerCase();
        for (var idx = 0; idx < list.length; idx++) {
          var item = list[idx];
          if (item.toLocaleLowerCase() === ilc) return item;
        }
      }
      return undefined;
    }
docs: Check if input exists in list in a case insensitive manner. Will return
  the value from the list rather than the user input so the list can control
  the final case.
  
  NOTE 1: The list may not contain, undefined, null or the empty string.
  NOTE 2: If there are multiple matches, the first one wins.
  
  @param {(string|boolean|undefined|null)} input
  @param {string[]} list
  @returns {(string|undefined)}