# File lib/active_support/cache.rb, line 55
    def self.lookup_store(*store_option)
      store, *parameters = *Array.wrap(store_option).flatten

      case store
      when Symbol
        store_class_name = store.to_s.camelize
        store_class =
          begin
            require "active_support/cache/#{store}"
          rescue LoadError => e
            raise "Could not find cache store adapter for #{store} (#{e})"
          else
            ActiveSupport::Cache.const_get(store_class_name)
          end
        store_class.new(*parameters)
      when nil
        ActiveSupport::Cache::MemoryStore.new
      else
        store
      end
    end