public interface Dynamic

The Dynamic interface provides methods for testing whether two objects have the same state, and for synchronizing states if they do not. The reason for such an interface is to assist with state salvation and restoration (see the Saveable interface). When we read a new list of Dynamic objects from a state file, we need a way to determine how closely the list in memory matches the one just read, as well as an efficient way to modify the existing list to conform to the one just read without necessarily recreating all those objects from scratch (which could be quite expensive). Thus, these "dynamic" objects implement the matches method to test if a freshly read dynamic object is in the same state as any of the current objects. If so, there is no need to reinitialize that object—we can just use the existing one. If not, we call the initState method to force the original object's state to conform to the one just read, without needing to recreate the object itself or relink it into data structures. The StateManager class contains the mergeStates static method, which performs this procedure on two lists of dynamic objects.