What is the best choice of test unit library for SAGE

edit

Now I'm using

import unittest

But I'm not sure that it is the best choice in SAGE context.

Something like this

import unittest

class Test(unittest.TestCase):
    def test_CheckLocalTestForI123(self):
      group = gap.GenerateG(2,5,3)
      generators = gap.GeneratorsOfGroup(group);

      subgroups = map(lambda gen: gap.Group(gen), generators);
      subgroups.reverse()

      self.assertNotEqual(CheckLocalTestForI123(group, subgroups, 1621, 1947, 1521), -1)

What are you using and why?