internal bool HasState(TRB_PART part, TRB_STATE state)
 {
     return(TimeBoxCollection.FirstOrDefault(trb => trb.HasState(part, state)) != null);
 }
 internal TimeBox TimeBoxGet(Guid uid)
 {
     return(TimeBoxCollection.FirstOrDefault(trb => trb.UID == uid));
 }
 internal bool TimeBoxContains(DateTime dt)
 {
     return(TimeBoxCollection.FirstOrDefault(trb => trb.Contains(dt)) != null);
 }