The method is designed to cancel changes made in an entity instance.
The method cancels modifications made in an entity instance. If an instance was deleted with TCustomEntityContext.Delete, the entity is restored from the object cache on the method execution, database access doesn't occur. The method cancels only those changes, that were not saved with the TCustomEntityContext.Save or TDataContext.SubmitChanges methods.
To cancel changes for all entities attached to the data context, the TDataContext.RejectChanges method is used.