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_DescribeTargetGroups.go
    path of file: ./repos/aws-sdk-go-v2/service/elasticloadbalancingv2
    
    the code of the file until where you have to start completion: // Code generated by smithy-go-codegen DO NOT EDIT.

package elasticloadbalancingv2

import (
	"context"
	"fmt"
	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
	"github.com/aws/aws-sdk-go-v2/service/elasticloadbalancingv2/types"
	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// Describes the specified target groups or all of your ta
    
func (p *DescribeTargetGroupsPaginator) NextPage(ctx context.Context, optFns ...func(*Options)) (*DescribeTargetGroupsOutput, error) {
	if !p.HasMorePages() {
		return nil, fmt.Errorf("no more pages available")
	}

	params := *p.params
	params.Marker = p.nextToken

	result, err := p.client.DescribeTargetGroups(ctx, &params, optFns...)
	if err != nil {
		return nil, err
	}
	p.firstPage = false

	prevToken := p.nextToken
	p.nextToken = result.NextMarker

	if p.options.StopOnDuplicateToken &&
		prevToken != nil &&
		p.nextToken != nil &&
		*prevToken == *p.nextToken {
		p.nextToken = nil
	}

	return result, nil
}