An EntityRec that manages two copies internally, a before and after, for 'undo' and comparison purposes.
An EntityRec Represents a 'Record' or set of Prop (names and values).
An EntityRec may also have DataAnnos (style annotations) that apply to the whole 'record'
An EntityRec that manages two copies internally, a before and after, for 'undo' and comparison purposes. An EntityRec Represents a 'Record' or set of Prop (names and values). An EntityRec may also have DataAnnos (style annotations) that apply to the whole 'record'