This method returns an array of all interval variables extracted by the invoking CP Optimizer engine. If the current model was not extracted or if it was changed since last extraction, this method will (re)extract it.

The main use case for this method is for accessing interval variables in the case when the model was read from a file using ImportModel(String).

Variables returned by this method can be used, for example, to query solution values using functions such as GetStart(IIntervalVar), GetEnd(IIntervalVar), GetLength(IIntervalVar), GetSize(IIntervalVar), IsPresent(IIntervalVar), IsAbsent(IIntervalVar).