def active?(url)
      # normalize the url
      url = URI(url)

      # session key
      key = key_for(url)

      return @sessions.has_key?(key)
    end
def active?(url)
      # normalize the url
      url = URI(url)

      # session key
      key = key_for(url)

      return @sessions.has_key?(key)
    end
Creates a new session cache.

 @param [Hash] options
   Configuration options.

 @option [Hash] :proxy (Spidr.proxy)
   Proxy options.

 @option [Integer] :open_timeout (Spidr.open_timeout)
   Optional open timeout.

 @option [Integer] :ssl_timeout (Spidr.ssl_timeout)
   Optional ssl timeout.

 @option [Integer] :read_timeout (Spidr.read_timeout)
   Optional read timeout.

 @option [Integer] :continue_timeout (Spidr.continue_timeout)
   Optional `Continue` timeout.

 @option [Integer] :keep_alive_timeout (Spidr.keep_alive_timeout)
   Optional `Keep-Alive` timeout.

 @since 0.6.0


 Determines if there is an active HTTP session for a given URL.

 @param [URI::HTTP, String] url
   The URL that represents a session.

 @return [Boolean]
   Specifies whether there is an active HTTP session.

 @since 0.2.3