Native function call in testcase using gwt-test-utils causes UnsatisfiedLinkError

Native function call in testcase using gwt-test-utils causes
UnsatisfiedLinkError

I am testing my gwt Composite component using gwt-test-utils 0.44.
I am using gwt-cal Calendar component. But i cant instantiate the class
beacause it throws UnstisfiedLinkError when a native function in invoked.
I have simulated the problem. Here is my code.
@GwtModule("com.testing.web.MyProject")
public class CalendarViewTest extends GwtTest{
private static native void alrt() /*-{
$wnd.alert("js");
}-*/;
@Test
public void test01(){
alrt();
}
}
This also causes UnstisfiedLinkError. How can i call the native funcion
correctly? Is there any configuration needed?