+ (components '())
+ (key #f))
+ (receive (e c k) (new-entity `((a . ,(make-a 1 2)) (b . ,(make-b))) entities components)
+ (set! entities e)
+ (set! components c)
+ (set! key k)
+ (display k) (newline))
+ (format #t "~a~%~a~%~%" entities components)
+
+ (receive (e c k) (new-entity `((a . ,(make-a 10 20))) entities components)
+ (set! entities e)
+ (set! components c)
+ (display k) (newline))
+ (format #t "~a~%~a~%~%" entities components)
+
+ (receive (e c) (set-entity-components key `((b . #f) (a . ,(make-a 50 50))) entities components)
+ (set! entities e)
+ (set! components c))
+ (format #t "~a~%~a~%~%" entities components)
+
+ (receive (e c) (remove-entity key entities components)
+ (set! entities e)
+ (set! components c))
+ (format #t "~a~%~a~%~%" entities components)
+
+ (receive (e c k) (new-entity `((a . ,(make-a 1 2)) (b . ,(make-b))) entities components)