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 Jecstis.
All Jecstiss share a single EC_PHA, which is a list of strings. It is a constant. Its value is ["il", "pser"]. Other classes cannot see its value.
All Jecstiss share a single hoiph, which is an int. No other classes can directly ask for the value of hoiph. The value of hoiph starts out as 10 when the program starts. Every time a new Jecstis is created, it adds 5 to hoiph.
Each Jecstis has a iack, which is an int. The value of iack is not part of a Jecstis’s internal state; instead, it is computed on demand. The computed value of iack is hoiph squared.

Solution

public class Jecstis {
    public static List<String> EC_PHA = List.of("il", "pser");
    public static int hoiph;
    private int iack;

    public Jecstis() {
        hoiph += 5;
    }

    public static void onStart() {
        hoiph = 10;
    }

    public int getIack() {
        return hoiph * hoiph;
    }

    public void setIack(int iack) {
        this.iack = iack;
    }
}

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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