/// <summary>
 /// Constructor that accepts values for all mandatory fields
 /// </summary>
 ///<param name="refId">GUID assigned to each statement at each level within the document hierarchy</param>
 ///<param name="language">A Language</param>
 ///<param name="standardHierarchyLevel">Integer assigned to each hierarchical level within standards tree. The top level is "1".</param>
 ///<param name="gradeLevels">For a description of this element, see 5.1.12 GradeLevels.</param>
 ///<param name="learningStandardDocumentRefId">The RefId of the item's parent LearningStandardDocument.</param>
 ///
 public LearningStandardItem(string refId, LanguageCode language, StandardHierarchyLevel standardHierarchyLevel, GradeLevels gradeLevels, string learningStandardDocumentRefId) : base(Adk.SifVersion, InstrDTD.LEARNINGSTANDARDITEM)
 {
     this.RefId = refId;
     this.SetLanguage(language);
     this.StandardHierarchyLevel        = standardHierarchyLevel;
     this.GradeLevels                   = gradeLevels;
     this.LearningStandardDocumentRefId = learningStandardDocumentRefId;
 }
 /// <summary>
 /// Constructor that accepts values for all mandatory fields
 /// </summary>
 ///<param name="refId">GUID assigned to each statement at each level within the document hierarchy</param>
 ///<param name="language">A Language</param>
 ///<param name="standardHierarchyLevel">Integer assigned to each hierarchical level within standards tree. The top level is "1".</param>
 ///<param name="gradeLevels">For a description of this element, see 5.1.12 GradeLevels.</param>
 ///<param name="learningStandardDocumentRefId">The RefId of the item's parent LearningStandardDocument.</param>
 ///
 public LearningStandardItem( string refId, LanguageCode language, StandardHierarchyLevel standardHierarchyLevel, GradeLevels gradeLevels, string learningStandardDocumentRefId )
     : base(Adk.SifVersion, InstrDTD.LEARNINGSTANDARDITEM)
 {
     this.RefId = refId;
     this.SetLanguage( language );
     this.StandardHierarchyLevel = standardHierarchyLevel;
     this.GradeLevels = gradeLevels;
     this.LearningStandardDocumentRefId = learningStandardDocumentRefId;
 }