gistfile1.java

public static Transaction deserialize(LinkedHashMap section) {
        if(!section.containsKey("sender") ||
          !section.containsKey("itemstack") ||
          !section.containsKey("timestamp") ||
          !section.containsKey("lifetime")) {
            return null;
        }
        
        final String sender = section.getString("sender");
        final ItemStack is = section.getItemStack("itemstack");
        final long timestamp = section.getLong("timestamp");
        final long lifetime = section.getLong("lifetime");

        return new Transaction(sender, is, timestamp, lifetime);
    }