anchor.diff:  
   ;;----------------------------------------------------------------------
   
  -(defclass sdl-api (cepl.host:api-1)
  +(defclass sdl-api (cepl.host:api-2)
     (;;
      (supports-multiple-contexts-p :initform nil)
      ;;
  
positive.code:     (assert context ()
              "CEPL.SDL2: Could not find a suitable context for CEPL.
  Your machine must support at least GL 3.3")
      (sdl2:gl-make-current surface context)
      context))
  
  (defvar *core-context* t)
  
  
negative.code:    ;;
     (surface-title-function :initform #'sdl-surface-title)
     ;;
     (set-surface-title-function :initform #'sdl-set-surface-title)
     ;;
     (make-gl-context-shared-with-current-context-function
      :initform #'make-shared-sdl-context)))
  
  (register-host 'sdl-api)
  
  