def test_get_single_element_at_end(self):
# arrange
arr = [4, 4, 5, 5, 7]
# act
result = get_single_element(arr)
# assert
self.assertEqual(7, result)
def test_get_single_element_one_element(self):
# arrange
arr = [2]
# act
result = get_single_element(arr)
# assert
self.assertEqual(2, result)
def test_get_single_element_upper_half(self):
# arrange
arr = [1, 1, 3, 3, 4, 4, 5, 5, 6, 9, 9]
# act
result = get_single_element(arr)
# assert
self.assertEqual(6, result)