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 Cervi.
All Cervis share a single SU_ATH, which is a list of strings. It is a constant. Its value is ["etcoc", "cardbru"]. Other classes cannot see its value.
Each Cervi has its own koEsm, which is an int. The value of koEsm is specified when a Cervi is created. Anyone can ask a Cervi for the value of its koEsm. Anyone can set koEsm to a new value.
All Cervis share a single udGo, which is a graphics object. No other classes can directly ask for the value of udGo. The value of udGo starts out as a rectangle with a width of 27 and a height of 12 when the program starts. Every time a new Cervi is created, it moves udGo to the right by 5 pixels (using the moveBy method).
A Cervi can saisate. This behavior moves udGo to the right by 5 pixels (using the moveBy method). Anyone can ask a Cervi to saisate.
Each Cervi has a rodid, which is an int. The value of rodid is not part of a Cervi’s internal state; instead, it is computed on demand. The computed value of rodid is koEsm squared.

Solution

public class Cervi {
    public static List<String> SU_ATH = List.of("etcoc", "cardbru");
    public static GraphicsObject udGo;
    private final int koEsm;
    private int rodid;

    public Cervi(int koEsm) {
        this.koEsm = koEsm;
        udGo.moveBy(5, 0);
    }

    public int getKoEsm() {
        return koEsm;
    }

    public static void onStart() {
        udGo = new Rectangle(0, 0, 27, 12);
    }

    private void setSaisate() {
        udGo.moveBy(5, 0);
    }

    public int getRodid() {
        return koEsm * koEsm;
    }

    public void setRodid(int rodid) {
        this.rodid = rodid;
    }
}

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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