final P2ProxyRepository p2repo = proxy.adaptToFacet(P2ProxyRepository.class);
final ChecksumPolicy checksumPolicy = p2repo.getChecksumPolicy();
if (checksumPolicy == null || !checksumPolicy.shouldCheckChecksum()
|| !(item instanceof DefaultStorageFileItem)) {
// there is either no need to validate or we can't validate the item content
return ChecksumPolicy.IGNORE;
}