package doubler.impl;

import doubler.Doubler;
import org.junit.Test;

public class DoublerImplTest {
    
    @Test
    public void testIt() {
        Doubler doubler = new DoublerImpl();
        assert doubler.doubleIt(2) == 4;
    }
}

@@ -62,16 +62,50 @@
 it.Test;
+%0Aimport static org.junit.Assert.*;
 %0A%0Apublic
@@ -133,13 +133,8 @@
 t %7B%0A
-    %0A
     
@@ -225,16 +225,25 @@
   assert
+Equals(4,
  doubler
@@ -258,13 +258,9 @@
 t(2)
- == 4
+)
 ;%0A  

Use JUnit assert method in test case