That seems to be the relevant part in the code:
org.peerfact.impl.application.filesharing.documents.FlatDocumentSet
public int getIdForLookup() { return startRank + rand.nextInt(size); }
# action file for FileSharing
all 1s-120m FileSharingApplication:join
all 120m-180m FileSharingApplication:publishResourcesFromSet files 100
all 180m FileSharingApplication:lookupResourceFromSetPeriodically files 10m
<?xml version='1.0' encoding='utf-8'?>
<ResourceSpace
class="org.peerfact.impl.application.filesharing.documents.DocumentSpace"
static="getInstance">
<ResourceSet
class="org.peerfact.impl.application.filesharing.documents.FlatDocumentSet"
name="files" size="100" />
</ResourceSpace>