@Test
public void mergedProductAttributes() {
stackedEnts.add(createEntFromPool(pool1));
stackedEnts.add(createEntFromPool(pool3));
PoolUpdate update = poolRules.updatePoolFromStack(stackDerivedPool);
assertTrue(update.changed());
assertTrue(update.getProductAttributesChanged());
assertEquals(6, stackDerivedPool.getProductAttributes().size());
assertEquals("2", stackDerivedPool.getProductAttributeValue("testattr2"));
assertEquals("1", stackDerivedPool.getProductAttributeValue("testattr1"));