from
If the type of a MPIAction is MPIActionType.TAKEVORTEX or MPIActionType.EXITVORTEX, fromMap represents the MPIMap of departure; otherwise, fromMap is null.
If the type of a MPIAction is MPIActionType.TAKEVORTEX or MPIActionType.EXITVORTEX, fromMap represents the MPIMap of departure; otherwise, fromMap is null.