diff --git a/swh/provenance/origin.py b/swh/provenance/origin.py
index c507faf..92c7cb0 100644
--- a/swh/provenance/origin.py
+++ b/swh/provenance/origin.py
@@ -1,89 +1,91 @@
-from typing import Optional
+from typing import List, Optional
 
 from swh.model.model import ObjectType, Origin, TargetType
 
 from .archive import ArchiveInterface
 from .model import OriginEntry, RevisionEntry
 
 ################################################################################
 ################################################################################
 
 
 class FileOriginIterator:
     """Iterator over origins present in the given CSV file."""
 
     def __init__(
         self, filename: str, archive: ArchiveInterface, limit: Optional[int] = None
     ):
         self.file = open(filename)
         self.limit = limit
         self.archive = archive
 
     def __iter__(self):
         yield from iterate_statuses(
             [Origin(url.strip()) for url in self.file], self.archive, self.limit
         )
 
 
 class ArchiveOriginIterator:
     """Iterator over origins present in the given storage."""
 
     def __init__(self, archive: ArchiveInterface, limit: Optional[int] = None):
         self.limit = limit
         self.archive = archive
 
     def __iter__(self):
         yield from iterate_statuses(
             self.archive.iter_origins(), self.archive, self.limit
         )
 
 
-def iterate_statuses(origins, archive: ArchiveInterface, limit: Optional[int] = None):
+def iterate_statuses(
+    origins: List[Origin], archive: ArchiveInterface, limit: Optional[int] = None
+):
     idx = 0
     for origin in origins:
         for visit in archive.iter_origin_visits(origin.url):
             for status in archive.iter_origin_visit_statuses(origin.url, visit.visit):
                 snapshot = archive.snapshot_get_all_branches(status.snapshot)
                 if snapshot is None:
                     continue
                 # TODO: may filter only those whose status is 'full'??
                 targets_set = set()
                 releases_set = set()
                 if snapshot is not None:
                     for branch in snapshot.branches:
                         if snapshot.branches[branch].target_type == TargetType.REVISION:
                             targets_set.add(snapshot.branches[branch].target)
                         elif (
                             snapshot.branches[branch].target_type == TargetType.RELEASE
                         ):
                             releases_set.add(snapshot.branches[branch].target)
 
                 # This is done to keep the query in release_get small, hence avoiding
                 # a timeout.
                 batchsize = 100
                 while releases_set:
                     releases = [
                         releases_set.pop() for i in range(batchsize) if releases_set
                     ]
                     for release in archive.release_get(releases):
                         if release is not None:
                             if release.target_type == ObjectType.REVISION:
                                 targets_set.add(release.target)
 
                 # This is done to keep the query in revision_get small, hence avoiding
                 # a timeout.
                 revisions = set()
                 while targets_set:
                     targets = [
                         targets_set.pop() for i in range(batchsize) if targets_set
                     ]
                     for revision in archive.revision_get(targets):
                         if revision is not None:
                             revisions.add(RevisionEntry(revision.id))
                             # target_set |= set(revision.parents)
 
                 yield OriginEntry(status.origin, list(revisions))
 
                 idx += 1
                 if idx == limit:
                     return