Write a testNG test for the method - *public String write (String word)* for the other methods I wrote tests

public class Pen {
    private int inkContainerValue = 1000;
    private double sizeLetter = 1.0;
    private String color = "BLUE";

    public String write(String word) {
        if (!isWork()) {
            return "";
        }
        double sizeOfWord = word.length() * sizeLetter;
        if (sizeOfWord <= inkContainerValue) {
            inkContainerValue -= sizeOfWord;
            return word;
        }
        String partOfWord = word.substring(0, inkContainerValue);
        inkContainerValue = 0;
        return partOfWord;
    }

Help write a testNG test for the method - public String write (String word) for the other methods I wrote tests