java.lang.IllegalArgumentException error when attempting to run Junit Tests

Question

I am trying to run a parameterized test with Junit but I keep getting the error java.lang.IllegalArgumentException. I have tried google the problem but I just cannot seem to figure it out exactly why this code is not working. Any feedback would be greatly appreciated.

package mainPackage;

import static org.junit.Assert.*;

import java.math.BigInteger;
import java.util.Arrays;
import java.util.Collection;

import org.hamcrest.Matcher;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

@RunWith(value = Parameterized.class)
public class IsPrimeTest {
    private String numA;
    private boolean expected;

    public void IsPrimeTest(String numA, boolean expected) {

        this.numA = numA;
        this.expected = expected;

    }

    @Parameters
    public static Collection<Object[]> data(){
        return Arrays.asList(new Object[][]{
            {"13", true}


        });
    }

    @Test
    public void ParameterizedTestIsPrime() {
        IsPrime test = new IsPrime();
        assertEquals(IsPrime.isPrime(new BigInteger(numA)), expected);
    }
}

Answer 1

public void IsPrimeTest(String numA, boolean expected) {

should be

public IsPrimeTest(String numA, boolean expected) {

Your constructor can't have a return type, else it's not a constructor.