how to learn and use ConflictResolution class?

I am in WindChil 9.0 M050.

Reference from Stephen Lawson. The URLlink is http://communities.ptc.com/message/199840.

I motified the method for deletion of the selective iterations.The result is OK.

But I don't clearly know ConflictResolution class after reading API.

I thinked the class that is for sloving the conflict when deleting latest object.

As the following, I don't know the attributes where come from.

ConflictResolution allowRollback = new ConflictResolution(VersionControlConflictType.LATEST_ITERATION_DELETE , VersionControlResolutionType.ALLOW_LATEST_ITERATION_DELETE);

Can anyone provide information about it?

And I have an other question :

I has deleted the latest iteration of wtdocument_A which had WTDocumentDependencyLink with wtdocument_B and WTPartDescribeLink with wtpart_C.

In other words, I don't remove the links before deleting the latest iteration.

what's wrong with it?

Thanks.