code: function normalizeString(val, normalizer) {
      if (!normalizer) {
          normalizer = (str) => str.toLowerCase().trim();
      }
      return normalizer(toStringSafe(val));
  }
docs: Normalizes a value as string so that is comparable.
  
  @param {any} val The value to convert.
  @param {(str: string) => string} [normalizer] The custom normalizer.
  
  @return {string} The normalized value.