private void addingSameItemTwiceHasNoEffect(ChildAdder childAdder, ChildrenQuery childrenQuery)
throws SDKException {
// Given
ManagedObjectRepresentation ch1 = inventory.create(aSampleMo().build());
ManagedObjectRepresentation ch2 = inventory.create(aSampleMo().build());
ManagedObjectReferenceRepresentation childRef1 = createChildRef(ch1);
ManagedObjectReferenceRepresentation childRef2 = createChildRef(ch2);
// When
childAdder.addChild(childRef1);
childAdder.addChild(childRef2);
childAdder.addChild(childRef1);
// Then
List<GId> childIds = getIdsOfChildren(childrenQuery);
assertThat(childIds, is(asList(ch1.getId(), ch2.getId())));
}