public override ErrorList Validate() { var result = new ErrorList(); result.AddRange(base.Validate()); if (Code != null) { Code.ForEach(elem => result.AddRange(elem.Validate())); } if (Period != null) { result.AddRange(Period.Validate()); } if (FacilityType != null) { result.AddRange(FacilityType.Validate()); } return(result); }