def test_valid_rotation(self):
        rotation = shifted_diff("coffee", "eecoff")
        self.assertEquals(rotation, 2)

        rotation = shifted_diff("eecoff", "coffee")
        self.assertEquals(rotation, 4)
 def test_with_no_rotation(self):
     rotation = shifted_diff("Esham", "Esham")
     self.assertEquals(rotation, 0)
 def test_invalid_rotation(self):
     rotation = shifted_diff("Moose", "moose")
     self.assertEquals(rotation, -1)
 def test_valid_rotation_with_special_characters(self):
     rotation = shifted_diff("isn't", "'tisn")
     self.assertEquals(rotation, 2)