def test_count_stack_empty_stack(self):
stack = StackArray()
self.assertEqual(0, stack.count())
def test_clear_stack(self):
stack = StackArray([9])
stack.clear()
self.assertEqual(0, stack.count())
self.assertEqual('', str(stack))
def test_count_stack(self):
stack = StackArray([4, 9])
self.assertEqual(2, stack.count())