(let (condition)
  (restart-case (request% …)
    (retry ()
      :test (lambda (c) (typep c 'http-error))
      :report "Retry the HTTP request."
      (recur))
    (confirm-payment ()
      :test (lambda (c)
              (when (typep c 'http-402-payment-required)
                (setf condition c) ; awful
                t))
      :report "Confirm payment and retry the HTTP request."
      (do-something condition)
      (recur))))