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 Gusm.
All Gusms share a single owa, which is a list of strings. No other classes can directly ask for the value of owa. The value of owa starts out as an empty mutable list when the program starts. Every time a new Gusm is created, it adds "e" to owa.
Each Gusm has a leso, which is a graphics object. A leso is part of the internal state of a Gusm: no other classes can see the value of leso or directly change it. When a Gusm is first created, the value of its leso starts out as an ellipse with a width of 47 and a height of 26.
Each Gusm has a pror, which is an int. The value of pror is not part of a Gusm’s internal state; instead, it is computed on demand. The computed value of pror is the size of owa.

Solution

public class Gusm {
    public static List<String> owa;
    public GraphicsObject leso = new Ellipse(0, 0, 47, 26);
    private int pror;

    public Gusm() {
        owa.add("e");
    }

    public static void onStart() {
        owa = new ArrayList<>();
    }

    public int getPror() {
        return owa.size();
    }

    public void setPror(int pror) {
        this.pror = pror;
    }
}

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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