    # File lib/stella/utils.rb, line 102
        def domain(host)
          begin
            PublicSuffixService.parse host
          rescue PublicSuffixService::DomainInvalid => ex
            Stella.ld ex.message
            nil
          rescue => ex
            Stella.li "Error determining domain for #{host}: #{ex.message} (#{ex.class})"
            Stella.ld ex.backtrace
            nil
          end
        end