The example gives the impression that draw! returns a copy like draw
img = testimage("lighthouse")
img_example_stage1 = draw!(img, Polygon(RectanglePoints(Point(10, 10), Point(100, 100))), RGB{N0f8}(1))
img_example_stage2 = draw!(img_example_stage1, Polygon(RectanglePoints(CartesianIndex(110, 10), CartesianIndex(200, 200))), RGB{N0f8}(1))
img_example_stage3 = draw!(img_example_stage2, Polygon(RectanglePoints(220, 10, 300, 300)), RGB{N0f8}(1))
save("images/lighthouse_rectangle.png", img); nothing # hide
The example gives the impression that
draw!returns a copy likedraw