'If an error happens during rollback, L{ConnectionLost} is raised but
the original error is logged.'

def test_rollbackErrorLogged(self):

    class ConnectionRollbackRaise(object, ):
        def rollback(self):
            raise RuntimeError('problem!')
    pool = FakePool(ConnectionRollbackRaise)
    connection = Connection(pool)
    self.assertRaises(ConnectionLost, connection.rollback)
    errors = self.flushLoggedErrors(RuntimeError)
    self.assertEqual(len(errors), 1)
    self.assertEqual(errors[0].value.args[0], 'problem!')
