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

package ssmcontacts

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

// Updates the information specified for an on-call rotation.
func (c *Client) UpdateRotation(ctx context.Context, params *UpdateRotationInput, optFns ...func(*Options)) (*UpdateRotationOutput, error) {
	if params == nil {
		params = &UpdateRotationInput{}
	}

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

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

type UpdateRotationInput struct {

	// Information about how long the updated rotation lasts before restarting at the
	// beginning of the shift order.
	//
	// This member is required.
	Recurrence *types.RecurrenceSettings

	// The Amazon Resource Name (ARN) of the rotation to update.
	//
	// This member is required.
	RotationId *string

	// The Amazon Resource Names (ARNs) of the contacts to include in the updated
	// rotation. The order in which you list the contacts is their shift order in the
	// rotation schedule.
	ContactIds []string

	// The date and time the rotation goes into effect.
	
    
func (c *Client) addOperationUpdateRotationMiddlewares(stack *middleware.Stack, options Options) (err error) {
	if err := stack.Serialize.Add(&setOperationInputMiddleware{}, middleware.After); err != nil {
		return err
	}
	err = stack.Serialize.Add(&awsAwsjson11_serializeOpUpdateRotation{}, middleware.After)
	if err != nil {
		return err
	}
	err = stack.Deserialize.Add(&awsAwsjson11_deserializeOpUpdateRotation{}, middleware.After)
	if err != nil {
		return err
	}
	if err := addProtocolFinalizerMiddlewares(stack, options, "UpdateRotation"); 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 = addOpUpdateRotationValidationMiddleware(stack); err != nil {
		return err
	}
	if err = stack.Initialize.Add(newServiceMetadataMiddleware_opUpdateRotation(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
}