The minimum amount of data we need to serialize to be able to reconstruct the graph as it was. Note that classes that inherit fromUGraphand its elements will no doubt want to extend the graph with actual information on each node/edge/island. In that case, they should extendFSerializableGraphto contain the extra information per graph handle. Furthermore, they'll need to extendUGraphto have its own typed serialization save/load functions that call the base functions inUGraphfirst.