code: function constructHumanReadableCurlsCacheDomain_(domain) {
    domain = punycode.toUnicode(domain);
    domain = domain.split('-').join('--');
    domain = domain.split('.').join('-');
    return punycode.toASCII(domain).toLowerCase();
  }
docs: Constructs a human readable curls encoded cache domain using the following
  algorithm:
  Convert domain from punycode to utf-8 (if applicable)
  Replace every '-' with '--'
  Replace every '.' with '-'
  Convert back to punycode (if applicable)
  
  @param {string} domain The publisher domain
  @return {string} The curls encoded domain
  @private