code: public static boolean isDomainSuffix(String domain, String domainSuffix) {
          if (domain.length() < domainSuffix.length()) {
              return false;
          }
          if (domain.length() == domainSuffix.length()) {
              return domain.equals(domainSuffix);
          }
  
          return domain.endsWith(domainSuffix) && domain.charAt(domain.length() - domainSuffix.length() - 1) == '.';
      }
docs: If domainSuffix is suffix of domain
  
  @param domain       start with "."
  @param domainSuffix not start with "."