public class Demo1 {
    
    public <T> void swap(T arr[], int pos1, int pos2) {
        T temp = arr[pos1];
        arr[pos1] = arr[pos2];
        arr[pos2] = temp;
    }
}

public class TestDemo {

    @Test
    public void test1() {
        int intArr[] = new int[] { 12, 13, 15, 14 };

        Demo1 d = new Demo1();

        d.swap(intArr, 1, 2);
    }
}