examples/ex-91.rkt
#lang racket
(require (planet wcy/mpost-wrapper))
(provide main)
(define (main)
  (let ((pic (unknown-picture)))
    (addto pic 'contour (fullcircle '1cm)
           #:withcolor (op* 0.8 'white))
    (addto pic 'doublepath (fullcircle '1cm)
           #:withpen (scale '0.5bp 'pencircle))
    (addto pic 'also (shift (point '1mm '1mm) pic))
    (draw pic)))