combinePlacements :: Maybe ([IndexedSpace], [ResidualSpace], PackingSelectors, ItemQuantityMap, Int)
                  -- ^ The currently placed packages, residual spaces, packing selecotrs, quantities and used chromosomes ('A')
               -> Maybe ([IndexedSpace], [ResidualSpace]) -- ^ To be added packages and to be replaced residual spaces ('B')
               -> Maybe ([IndexedSpace], [ResidualSpace], PackingSelectors, ItemQuantityMap, Int) -- ^ The resulting update of the state
combinePlacements Nothing _ = Nothing
combinePlacements :: Maybe ([IndexedSpace], [ResidualSpace], PackingSelectors, ItemQuantityMap, Int)
                  -- ^ The currently placed packages, residual spaces, packing selecotrs, quantities and used chromosomes ('A')
               -> Maybe ([IndexedSpace], [ResidualSpace]) -- ^ To be added packages and to be replaced residual spaces ('B')
               -> Maybe ([IndexedSpace], [ResidualSpace], PackingSelectors, ItemQuantityMap, Int)
combinePlacements Nothing _ = Nothing
combinePlacements Nothing _ = Nothing