1 

     2 val urban_prices = List(List(Some(71.539941), None), 

     3                         List(Some(76.974614), None), 

     4                         List(Some(65.226685), Some(6.35)), 

     5                         List(Some(78.354649), Some(12.241)), 

     6                         List(Some(85.517645), Some(38.188)))

     7 

     8 val urban_deltas = List(List(Some(0.07596697626574789), None), 

     9                         List(Some(-0.152620823795232), None), 

    10                         List(Some(0.20126676681483952), Some(0.9277165354330709)), 

    11                         List(Some(0.09141762603007778), Some(2.119679764725104)))

    12 

    13 

    14 assert (get_deltas(get_prices(List("IBM", "BIDU"), 2004 to 2008)) == urban_deltas)

    15