Rename _compute_groups to compute_groups

Signed-off-by: Niels Thykier <niels@thykier.net>

britney.py

@@ -1507,7 +1507,7 @@ class Britney(object):
 
         for y in sorted((y for y in packages), key=attrgetter('uvname')):
             try:
-                updates, rms, _ = mm._compute_groups(y)
+                updates, rms, _ = mm.compute_groups(y)
                 result = (y, frozenset(updates), frozenset(rms))
                 group_info[y] = result
             except MigrationConstraintException as e:

britney2/migration.py

@@ -49,7 +49,7 @@ class MigrationManager(object):
     def current_transaction(self):
         return self._transactions[0] if self._transactions else None
 
-    def _compute_groups(self,
+    def compute_groups(self,
                        item,
                        allow_smooth_updates=True,
                        removals=frozenset()):
@@ -240,7 +240,7 @@ class MigrationManager(object):
         pkg_universe = self.pkg_universe
         transaction = self.current_transaction
 
-        updates, rms, _ = self._compute_groups(item, removals=removals)
+        updates, rms, _ = self.compute_groups(item, removals=removals)
 
         # Handle the source package
         if item.architecture == 'source':
@@ -374,7 +374,7 @@ class MigrationManager(object):
             affected_direct = set()
             affected_all = set()
             for item in items:
-                _, rms, _ = self._compute_groups(item, allow_smooth_updates=False)
+                _, rms, _ = self.compute_groups(item, allow_smooth_updates=False)
                 removals.update(rms)
                 affected_architectures.add(item.architecture)