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: update_endpoint.go
    path of file: ./repos/buildkit/vendor/github.com/aws/aws-sdk-go-v2/service/s3/internal/customizations
    
    the code of the file until where you have to start completion: package customizations

import (
	"context"
	"fmt"
	"log"
	"net/url"
	"strings"

	"github.com/aws/aws-sdk-go-v2/aws"
	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
	"github.com/aws/aws-sdk-go-v2/service/internal/s3shared"
	internalendpoints "github.com/aws/aws-sdk-go-v2/service/s3/internal/endpoints"
	"github.com/aws/smithy-go/encoding/httpbinding"
	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// EndpointResolver interface for resolving service endpoints.
type EndpointResolver interface {
	ResolveEndpoint(region string, options EndpointResolverOptions) (aws.Endpoint, error)
    
func dnsCompatibleBucketName(bucket string) bool {
	if strings.Contains(bucket, "..") {
		return false
	}

	// checks for `^[a-z0-9][a-z0-9\.\-]{1,61}[a-z0-9]$` domain mapping
	if !((bucket[0] > 96 && bucket[0] < 123) || (bucket[0] > 47 && bucket[0] < 58)) {
		return false
	}

	for _, c := range bucket[1:] {
		if !((c > 96 && c < 123) || (c > 47 && c < 58) || c == 46 || c == 45) {
			return false
		}
	}

	// checks for `^(\d+\.){3}\d+$` IPaddressing
	v := strings.SplitN(bucket, ".", -1)
	if len(v) == 4 {
		for _, c := range bucket {
			if !((c > 47 && c < 58) || c == 46) {
				// we confirm that this is not a IP address
				return true
			}
		}
		// this is a IP address
		return false
	}

	return true
}