code: function isEligibleForHumanReadableCacheEncoding_(domain) {
    const unicode = punycode.toUnicode(domain);
    return domain.length <= MAX_DOMAIN_LABEL_LENGTH_ &&
      !(HAS_LTR_CHARS.test(unicode) &&
        HAS_RTL_CHARS.test(unicode)) &&
      domain.indexOf('.') != -1;
  }
docs: Determines whether the given domain can be validly encoded into a human
  readable curls encoded cache domain.  A domain is eligible as long as:
  It does not exceed 63 characters
  It does not contain a mix of right-to-left and left-to-right characters
  It contains a dot character
  
  @param {string} domain The domain to validate
  @return {boolean}
  @private