public sealed class AssetType : ArcGIS.Core.CoreObjectsBase, System.IDisposable  

{
  // This routine creates a structural attachment association between a pole and a transformer bank
  static void CreateUNAssociation(UtilityNetwork utilityNetwork, AssetType poleAssetType, Guid poleGlobalID, AssetType transformerBankAssetType, Guid transformerBankGlobalID)
  {
    // Create edit operation
    EditOperation editOperation = new EditOperation();
    editOperation.Name = "Create structural attachment association";

    // Create a RowHandle for the pole
    Element poleElement = utilityNetwork.CreateElement(poleAssetType, poleGlobalID);
    RowHandle poleRowHandle = new RowHandle(poleElement, utilityNetwork);

    // Create a RowHandle for the transformer bank
    Element transformerBankElement =
      utilityNetwork.CreateElement(transformerBankAssetType, transformerBankGlobalID);
    RowHandle transformerBankRowHandle = new RowHandle(transformerBankElement, utilityNetwork);

    // Attach the transformer bank to the pole
    AssociationDescription structuralAttachmentAssociationDescription =
      new AssociationDescription(AssociationType.Attachment, poleRowHandle, transformerBankRowHandle);
    editOperation.Create(structuralAttachmentAssociationDescription);
    editOperation.Execute();
  }
}