import unittest


class TestSetOfStacks(unittest.TestCase):

    def test_set_of_stacks(self):
        print('Test: Push on an empty stack')
        stacks = SetOfStacks(indiv_stack_capacity=2)
        stacks.push(3)

        print('Test: Push on a non-empty stack')
        stacks.push(5)

        print('Test: Push on a capacity stack to create a new one')
        stacks.push('a')

        print('Test: Pop on a stack to destroy it')
        self.assertEqual(stacks.pop(), 'a')

        print('Test: Pop general case')
        self.assertEqual(stacks.pop(), 5)
        self.assertEqual(stacks.pop(), 3)

        print('Test: Pop on no elements')
        self.assertEqual(stacks.pop(), None)

        print('Success: test_set_of_stacks')


def main():
    test = TestSetOfStacks()
    test.test_set_of_stacks()


if __name__ == '__main__':
    main()