Implement the four_petal_flower function to recreate the following graphic.

Since the graphic is mainly composed by circles, let's first create a circle function that only takes a diameter and a color, using the ellipse function, since the latter takes three parameters but two are enough to construct a circle.

Now you can implement the wanted graphic more easily. Use the specified PETAL_COLOR and PISTIL_COLOR colors to achieve the same result as us.

Hint: you don't need to use pin and compose, but only beside, above and overlay.