def testCheckoutNoCreate(self):
    """Test init with previous branch existing."""
    self.PatchObject(self._branch, 'Exists', return_value=True)
    cros_mark_as_stable.GitBranch.Checkout(self._branch)
    self.git_mock.assert_called_with('.', ['checkout', '-f', self._branch_name],
                                     quiet=True)