resolveDependencies :: (Applicative m, Monad m)
                    => Maybe Int
                    -> Map PackageName (Set PackageName,Maybe Version)
                    -> (PackageName -> m (Set PackageName, Maybe Version))
                    -> m (Map PackageName (Set PackageName,Maybe Version))
resolveDependencies (Just 0) graph _ = return graph
resolveDependencies :: (Applicative m, Monad m)
                    => Maybe Int
                    -> Map PackageName (Set PackageName,Maybe Version)
                    -> (PackageName -> m (Set PackageName, Maybe Version))
                    -> m (Map PackageName (Set PackageName,Maybe Version))
resolveDependencies (Just 0) graph _ = return graph
resolveDependencies (Just 0) graph _ = return graph