# File httpd/lib/symbiosis/apache_logger.rb, line 18
    def [](k)
      now = @clock.call

      domain, cached_at = @cache[k]

      if ( !domain.is_a?(Symbiosis::Domain) or !cached_at.is_a?(now.class) or ( cached_at + @cache_time ) <= now )
        domain    = Symbiosis::Domains.find(k, @prefix)
        @cache[k] = [ domain, now ]
      end

      domain
    end