if(mappingCopyGroup == null) {
FetchGroupManager referenceFetchGroupManager = referenceDescriptor.getFetchGroupManager();
if(referenceFetchGroupManager != null) {
EntityFetchGroup nonReferenceEntityFetchGroup = referenceFetchGroupManager.getNonReferenceEntityFetchGroup(copyGroup.shouldResetPrimaryKey(), copyGroup.shouldResetVersion());
if(nonReferenceEntityFetchGroup != null) {
mappingCopyGroup = nonReferenceEntityFetchGroup.toCopyGroup();
} else {
// null nonReferenceEntityFetchGroup is equivalent to containing all attributes:
// create a new empty CopyGroup.
mappingCopyGroup = new CopyGroup();
mappingCopyGroup.shouldCascadeTree();