public AssociationDescription( 
   AssociationType type,
   RowHandle row1,
   RowHandle row2
)

// 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();

// Create an EditOperation
EditOperation editOperation = new EditOperation();
editOperation.Name = "Create pole; create transformer bank; attach transformer bank to pole";

// Create the transformer bank
RowToken transformerBankToken = editOperation.Create(transformerBankLayer, transformerBankAttributes);

// Create a pole
RowToken poleToken = editOperation.Create(poleLayer, poleAttributes);

// Create a structural attachment association between the pole and the transformer bank
RowHandle poleHandle = new RowHandle(poleToken);
RowHandle transformerBankHandle = new RowHandle(transformerBankToken);

AssociationDescription poleAttachment = new AssociationDescription(AssociationType.Attachment, poleHandle, transformerBankHandle);

editOperation.Create(poleAttachment);

// Execute the EditOperation
editOperation.Execute();