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 Frerm.
All Frerms share a single AR_REAEXIR, which is a string. It is a constant. Its value is "frutrid". Other classes cannot see its value.
All Frerms share a single keFi, which is a list of strings. No other classes can directly ask for the value of keFi. The value of keFi starts out as an empty mutable list when the program starts. Every time a new Frerm is created, it adds "untas" to keFi.
Each Frerm has its own oss, which is an int. The value of oss starts out as 13. Anyone can ask a Frerm for the value of its oss. Anyone can set oss to a new value.
Each Frerm has its own iard, which is a list of strings. The value of iard is specified when a Frerm is created. Anyone can ask a Frerm for the value of its iard. The value of iard for a specific Frerm can never change.
Each Frerm has a umEr, which is a string. An umEr is part of the internal state of a Frerm: no other classes can see the value of umEr or directly change it. When a Frerm is first created, the value of its umEr starts out as "rhil".
Each Frerm has a ong, which is an int. An ong is part of the internal state of a Frerm: no other classes can see the value of ong or directly change it. When a Frerm is first created, the value of its ong starts out as 1.
All Frerms share a single OSH_RITGRESS, which is an int. It is a constant. Its value is 1. Other classes can see its value.
Each Frerm has a ard, which is an int. The value of ard is not part of a Frerm’s internal state; instead, it is computed on demand. The computed value of ard is the size of keFi.
A Frerm can ismitate. This behavior adds "erdud" to umEr. Anyone can ask a Frerm to ismitate.
Each Frerm has a ceu, which is an int. The value of ceu is not part of a Frerm’s internal state; instead, it is computed on demand. The computed value of ceu is OSH_RITGRESS squared.
A Frerm can cirodize. This behavior adds "esser" to keFi. Anyone can ask a Frerm to cirodize.
Each Frerm has a liris, which is a string. The value of liris is not part of a Frerm’s internal state; instead, it is computed on demand. The computed value of liris is the first element of keFi.
A Frerm can whedize. This behavior adds "nelin" to umEr. Anyone can ask a Frerm to whedize.

Solution

public class Frerm {
    public static String AR_REAEXIR = "frutrid";
    public static List<String> keFi;
    private final int oss;
    private List<String> iard;
    public String umEr = "rhil";
    public int ong = 1;
    private final int OSH_RITGRESS = 1;
    private int ard;
    private int ceu;
    private String liris;

    public Frerm(List<String> iard) {
        keFi.add("untas");
        this.iard = iard;
    }

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

    public int getOss() {
        return oss;
    }

    public List<String> getIard() {
        return iard;
    }

    public void setIard(List<String> iard) {
        this.iard = iard;
    }

    public int getArd() {
        return keFi.size();
    }

    public void setArd(int ard) {
        this.ard = ard;
    }

    private void setIsmitate() {
        umEr += "erdud";
    }

    public int getCeu() {
        return OSH_RITGRESS * OSH_RITGRESS;
    }

    public void setCeu(int ceu) {
        this.ceu = ceu;
    }

    private void setCirodize() {
        keFi.add("esser");
    }

    public String getLiris() {
        return keFi.get(0);
    }

    public void setLiris(String liris) {
        this.liris = liris;
    }

    private void setWhedize() {
        umEr += "nelin";
    }
}

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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