Using Java how can I write a tester class for this?

public class ConverterClass {

 //Area convert }public static double sqydTOsqin(double sqyd) { return 1296 * sqyd; }public static double sqydTOsqmeter(double sqyd) { return 0.836127 * sqyd; }public static double sqydTOsqft(double sqyd) { return 9 * sqyd; }public static double sqmileTOsqin(double sqmile) { return 4.014E9 * sqmile; }public static double sqmileTOsqft(double sqmile) { return 2.788E7 * sqmile; }public static double sqmileTOsqyd(double sqmile) { return 3.098E6 * sqmile;

} } }