'Test that Youtube IDs which aren\'t explicitly set aren\'t included in the output string.'

def test_create_youtube_string_missing(self):

    self.descriptor.youtube_id_0_75 = 'izygArpw-Qo'
    self.descriptor.youtube_id_1_0 = 'p2Q6BrNhdh8'
    self.descriptor.youtube_id_1_25 = '1EeWXzPdhSA'
    expected = '0.75:izygArpw-Qo,1.00:p2Q6BrNhdh8,1.25:1EeWXzPdhSA'
    self.assertEqual(create_youtube_string(self.descriptor), expected)
