# File lib/rack/cascade.rb, line 19
    def call(env)
      result = NotFound

      last_body = nil

      @apps.each do |app|
        # The SPEC says that the body must be closed after it has been iterated
        # by the server, or if it is replaced by a middleware action. Cascade
        # replaces the body each time a cascade happens. It is assumed that nil
        # does not respond to close, otherwise the previous application body
        # will be closed. The final application body will not be closed, as it
        # will be passed to the server as a result.
        last_body.close if last_body.respond_to? :close

        result = app.call(env)
        last_body = result[2]
        break unless @catch.include?(result[0].to_i)
      end

      result
    end