anchor.diff:    (check-type description string)
     (alexandria:with-gensyms (g-category g-name)
       `(let ((,g-name ,name)
  -           (,g-category ,category))
  +           (,g-category ',(alexandria:symbolicate category)))
          (setf (gethash (drawing-test-keyname ,g-category ,g-name) *drawing-tests*)
                (make-drawing-test :category ,g-category
                                   :name ,g-name
                                   :description ,description
                                   :display-function (lambda (,frame ,stream ,@arglist) ,@body)))
  -       (pushnew ,g-category *drawing-tests-categories* :test #'string-equal))))
  +       (pushnew ,g-category *drawing-tests-categories*))))
   
   (defun get-display (category name)
     (let ((drawing-test (gethash (drawing-test-keyname category name) *drawing-tests*)))
  
positive.code: ;;; Clipping
  ;;;
  
  (define-drawing-test "Clipping region" "ellipse" (frame stream)
      "Non-rectangular clipping region. We should see grey rotated ellipse with
  limited angle drawn inside green border. This ellipse is a clipping region. Then
  we randomly drawn points on the screen which should be clipped to the grey area."
  
negative.code:                             (drawing-test-name test)))))))
  
  (defun drawing-test-pdf (test &optional filename)
    (let* ((test (if (symbolp test) (gethash test *drawing-tests*) test))
           (filename (or filename (format nil "/tmp/~a-~a.pdf"
                                          (drawing-test-category test)
                                          (drawing-test-name test)))))
  