An object history event where the object is assumed to be a graph object.
Package charger.history Description
Classes to maintain a history for any graph object.
A history consists of a series of events, each of which captures some transformation
in the object. The main events tracked are when an object is created by a user,
when an object is edited by a user, when an object is read from a file,
and when an object is derived by some procedure involving other graphs.