expand_cache_key

# File activesupport/lib/active_support/cache.rb, line 20
    def self.expand_cache_key(key, namespace = nil)
      expanded_cache_key = namespace ? "#{namespace}/" : ""
      
      if ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]
        expanded_cache_key << "#{ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]}/" 
      end

      expanded_cache_key << case
      when key.respond_to?(:cache_key)
        key.cache_key
      when key.is_a?(Array)
        key.collect { |element| expand_cache_key(element) }.to_param
      when key.respond_to?(:to_param)
        key.to_param
      end

      expanded_cache_key
    end