import unittest
from dec import *

class TestEx1(unittest.TestCase):
    def test_simple_double(self):
        @double
        def f():
            return 10

        self.assertEqual(f(), 20)

    def test_with_string(self):
        @double
        def f():
            return "abc"

        self.assertEqual(f(), "abcabc")

if __name__ == '__main__':
    unittest.main()