# File lib/moneta/builder.rb, line 48
    def adapter(adapter, options = {}, &block)
      case adapter
      when Symbol
        use(Adapters.const_get(adapter), options, &block)
      when Class
        use(adapter, options, &block)
      else
        raise ArgumentError, 'Adapter must be a Moneta store' unless adapter.respond_to?(:load) && adapter.respond_to?(:store)
        raise ArgumentError, 'No options allowed' unless options.empty?
        @proxies.unshift adapter
        nil
      end
    end