Constructor call must be the first statement in a constructor when there is no constructor call at all

I am trying to write unit tests for the code provided in http://ift.tt/rZcYOR

I am stuck in the first line though. My test looks like this:

public class fibonacciHeapTest {


    fibonacciHeap<Integer> fibHeap= new fibonacciHeap<>();

    @Test(expected = HeapEmptyException.class)
    public void testGetMin() throws HeapEmptyException {

        System.assert(true, fibHeap.isEmpty()); // Here I get the error mentioned in the title.

    }

Also the same line when looked at System, gives the following message int he dropdown : System cannot be resolved into a variable.

What am I doing wrong ? Thank you.