You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: api_op_CreateSiteToSiteVpnAttachment.go
    path of file: ./repos/aws-sdk-go-v2/service/networkmanager
    
    the code of the file until where you have to start completion: // Code generated by smithy-go-codegen DO NOT EDIT.

package networkmanager

import (
	"context"
	"fmt"
	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
	"github.com/aws/aws-sdk-go-v2/service/networkmanager/types"
	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// Creates an Amazon Web Services site-to-site VPN attachment on an edge location
// of a core network.
func (c *Client) CreateSiteToSiteVpnAttachment(ctx context.Context, params *CreateSiteToSiteVpnAttachmentInput, optFns ...func(*Options)) (*CreateSiteToSiteVpnAttachmentOutput, error) {
	if params == nil {
		params = &CreateSiteToSiteVpnAttachmentInput{}
	}

	result, metadata, err := c.invokeOperation(ctx, "CreateSiteToSiteVpnAttachment", params, optFns, c.addOperationCreateSiteToSiteVpnAttachmentMiddlewares)
	if err != nil {
		return nil, err
	}

	out := result.(*CreateSiteToSiteVpnAttachmentOutput)
	out.ResultMetadata = metadata
	return out, nil
}

type CreateSiteToSiteVpnAttachmentInput struct {

	// The ID of a core network where you're creating a site-to-site VPN attachment.
	//
	// This member is required.
	CoreNetworkId *string

	// The ARN identifying the 
    
func (c *Client) addOperationCreateSiteToSiteVpnAttachmentMiddlewares(stack *middleware.Stack, options Options) (err error) {
	if err := stack.Serialize.Add(&setOperationInputMiddleware{}, middleware.After); err != nil {
		return err
	}
	err = stack.Serialize.Add(&awsRestjson1_serializeOpCreateSiteToSiteVpnAttachment{}, middleware.After)
	if err != nil {
		return err
	}
	err = stack.Deserialize.Add(&awsRestjson1_deserializeOpCreateSiteToSiteVpnAttachment{}, middleware.After)
	if err != nil {
		return err
	}
	if err := addProtocolFinalizerMiddlewares(stack, options, "CreateSiteToSiteVpnAttachment"); err != nil {
		return fmt.Errorf("add protocol finalizers: %v", err)
	}

	if err = addlegacyEndpointContextSetter(stack, options); err != nil {
		return err
	}
	if err = addSetLoggerMiddleware(stack, options); err != nil {
		return err
	}
	if err = addClientRequestID(stack); err != nil {
		return err
	}
	if err = addComputeContentLength(stack); err != nil {
		return err
	}
	if err = addResolveEndpointMiddleware(stack, options); err != nil {
		return err
	}
	if err = addComputePayloadSHA256(stack); err != nil {
		return err
	}
	if err = addRetry(stack, options); err != nil {
		return err
	}
	if err = addRawResponseToMetadata(stack); err != nil {
		return err
	}
	if err = addRecordResponseTiming(stack); err != nil {
		return err
	}
	if err = addClientUserAgent(stack, options); err != nil {
		return err
	}
	if err = smithyhttp.AddErrorCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = smithyhttp.AddCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = addSetLegacyContextSigningOptionsMiddleware(stack); err != nil {
		return err
	}
	if err = addIdempotencyToken_opCreateSiteToSiteVpnAttachmentMiddleware(stack, options); err != nil {
		return err
	}
	if err = addOpCreateSiteToSiteVpnAttachmentValidationMiddleware(stack); err != nil {
		return err
	}
	if err = stack.Initialize.Add(newServiceMetadataMiddleware_opCreateSiteToSiteVpnAttachment(options.Region), middleware.Before); err != nil {
		return err
	}
	if err = addRecursionDetection(stack); err != nil {
		return err
	}
	if err = addRequestIDRetrieverMiddleware(stack); err != nil {
		return err
	}
	if err = addResponseErrorMiddleware(stack); err != nil {
		return err
	}
	if err = addRequestResponseLogging(stack, options); err != nil {
		return err
	}
	if err = addDisableHTTPSMiddleware(stack, options); err != nil {
		return err
	}
	return nil
}