'Traverse commits and add them to the view.'

def add_commits(self, commits):

    self.commits.extend(commits)
    scene = self.scene()
    for commit in commits:
        item = Commit(commit, self.notifier)
        self.items[commit.oid] = item
        for ref in commit.tags:
            self.items[ref] = item
        scene.addItem(item)
    self.layout_commits()
    self.link(commits)
