def test_resource_find_pieces(self):
''' test that we can find a piece in the cake '''
keys = ['red', 'blue', 'green', 'yellow', 'orange', 'purple']
vals = dict((k, F(1,1)) for k in keys)
cake = CollectionResource(keys)
user = CollectionPreference('mark', vals)
piece = cake.find_piece(user, 3)
actual = CollectionResource(['red', 'blue', 'green'])
self.assertEqual(piece.value, actual.value)
vals = {'red':10, 'blue':20, 'green':30, 'yellow':15, 'orange':25}
keys = vals.keys()
cake = CollectionResource(keys)
user = CollectionPreference('mark', vals)
self.assertEqual(50, user.value_of(cake.find_piece(user, 50)))
self.assertEqual(60, user.value_of(cake.find_piece(user, 60)))
self.assertEqual(70, user.value_of(cake.find_piece(user, 70)))
vals = {'red':10, 'blue':20, 'green':30, 'orange':40}
keys = vals.keys()
cake = CollectionResource(keys)
user = CollectionPreference('mark', vals)
self.assertEqual(50, user.value_of(cake.find_piece(user, 50)))
self.assertEqual(60, user.value_of(cake.find_piece(user, 60)))
self.assertEqual(70, user.value_of(cake.find_piece(user, 70)))
self.assertRaises(ValueError, lambda: cake.find_piece(user, 150))
