@Test(
     expectedExceptions = NullPointerException.class,
     expectedExceptionsMessageRegExp = "DataHash can not be null")
 public void testCreateAggregationRequestWithoutDataHash_ThrowsNullPointerException()
     throws Exception {
   pduFactory.createAggregationRequest(requestContext, null, DEFAULT_LEVEL);
 }
 @Test(
     expectedExceptions = IllegalArgumentException.class,
     expectedExceptionsMessageRegExp = "Only non-negative integer values are allowed")
 public void testCreateAggregationRequestWithNegativeLevel_ThrowsNullPointerException()
     throws Exception {
   pduFactory.createAggregationRequest(requestContext, dataHash, -42L);
 }
 @Test
 public void testCreateAggregationRequest_Ok() throws Exception {
   AggregationRequest request =
       pduFactory.createAggregationRequest(requestContext, dataHash, DEFAULT_LEVEL);
   Assert.assertNotNull(request);
 }