new

# File actionpack/lib/action_dispatch/middleware/session/abstract_store.rb, line 139
      def initialize(app, options = {})
        @app = app
        @default_options = DEFAULT_OPTIONS.merge(options)
        @key = @default_options.delete(:key).freeze
        @cookie_only = @default_options.delete(:cookie_only)
        ensure_session_key!
      end