public void setExits(Room north, Room east, Room south, Room west, Room up, Room down) 
    {
        if(north != null)
            exits.put("North", north);
        if(east != null)
            exits.put("East", east);
        if(south != null)
            exits.put("South", south);
        if(west != null)
            exits.put("West", west);
        if(up != null)
            exits.put("Up", up);
        if(up != null)
            exits.put("Down", down);
        
    }