Class declarations and object modeling: Correct Solution

Translate the specification below into an idiomatic Java class definition.

(In this context, "idiomatic" means following the common style and conventions of the language.)

One kind of thing that exists in our model is a Scru.
All Scrus share a single rart, which is a graphics object. No other classes can directly ask for the value of rart. The value of rart starts out as an ellipse with a width of 37 and a height of 19 when the program starts. Every time a new Scru is created, it moves rart to the right by 4 pixels (using the moveBy method).

Solution

public class Scru {
    public static GraphicsObject rart;

    public Scru() {
        rart.moveBy(4, 0);
    }

    public static void onStart() {
        rart = new Ellipse(0, 0, 37, 19);
    }
}

Things to check in your solution:

Is every public and private modifier correct?
Are the correct items static?
Are the correct items final?
Are all the variable types and method return types correct?
Are the class members in the correct order? It should be: (1) static variables, (2) instance variables, (3) constructors, (4) methods.
Do members have the correct capitalization?

Acceptable variations in the solution:

It is OK if you initialized non-static variables in the constructor instead of in the declaration. (Ask your instructor if you aren’t clear what this means.) Note that static variables must be initialized in the declaration.
It is OK if you used a slightly different but equivalent form of an expression, such as += 1 instead of ++.

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