# File lib/dragonfly/app.rb, line 130
    def use_datastore(store, *args)
      self.datastore = if store.is_a?(Symbol)
        get_klass = self.class.available_datastores[store]
        raise UnregisteredDataStore, "the datastore '#{store}' is not registered" unless get_klass
        klass = get_klass.call
        klass.new(*args)
      else
        raise ArgumentError, "datastore only takes 1 argument unless you use a symbol" if args.any?
        store
      end
      raise "datastores have a new interface (read/write/destroy) - see docs at http://markevans.github.io/dragonfly for details" if datastore.respond_to?(:store) && !datastore.respond_to?(:write)
    end