def method_missing(name, &block)
      @formats.push([name, block || proc {}]) unless @formats.any? {|n,b| n == name}
    end
def method_missing(name, &block)
      @formats.push([name, block || proc {}]) unless @formats.any? {|n,b| n == name}
    end
Returns a new Response with no format data.
 Used to dispatch the individual format methods.