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_CreateDBSnapshot.go
    path of file: ./repos/aws-sdk-go-v2/service/rds
    
    the code of the file until where you have to start completion: // Code generated by smithy-go-codegen DO NOT EDIT.

package rds

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

// Creates a snapshot of a DB instance. The source DB instance must be in the
// available or storage-optimization state.
func (c *Client) CreateDBSnapshot(ctx context.Context, params *CreateDBSnapshotInput, optFns ...func(*Options)) (*CreateDBSnapshotOutput, error) {
	if params == nil {
		params = &CreateDBSnapshotInput{}
	}

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

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

type CreateDBSnapshotInput struct {

	// The identifier of the DB instance that you want to create the snapshot of.
	// Constraints:
	//   - Must match the identifier of an existing DBInstance.
	//
	// This member is required.
	DBInstanceIdentifier *string

	// The identifier for the DB snapshot. Constraints:
	//   - Can't be null, empty, or blank
	//   - Must contain from 1 to 255 letters, numbers, or hyphens
	//   - First character must be a letter
	//   - Can't end with a hyphen or contain two consecutive hyphens
	// Example: my-snapshot-id
	//
	//
    
func (c *Client) addOperationCreateDBSnapshotMiddlewares(stack *middleware.Stack, options Options) (err error) {
	if err := stack.Serialize.Add(&setOperationInputMiddleware{}, middleware.After); err != nil {
		return err
	}
	err = stack.Serialize.Add(&awsAwsquery_serializeOpCreateDBSnapshot{}, middleware.After)
	if err != nil {
		return err
	}
	err = stack.Deserialize.Add(&awsAwsquery_deserializeOpCreateDBSnapshot{}, middleware.After)
	if err != nil {
		return err
	}
	if err := addProtocolFinalizerMiddlewares(stack, options, "CreateDBSnapshot"); 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 = addOpCreateDBSnapshotValidationMiddleware(stack); err != nil {
		return err
	}
	if err = stack.Initialize.Add(newServiceMetadataMiddleware_opCreateDBSnapshot(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
}