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: main.go
    path of file: ./repos/awless/vendor/github.com/aws/aws-sdk-go/example/aws/credentials/plugincreds
    
    the code of the file until where you have to start completion: // +build example,go18

package main

import (
	"context"
	"fmt"
	"os"
	"plugin"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/credentials/plugincreds"
	"github.com/aws/aws-sdk-go/aws/endpoints"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/
    
func main() {
	if len(os.Args) < 4 {
		exitErrorf("Usage: myApp <compiled plugin>, <bucket> <object key>")
	}

	pluginFilename := os.Args[1]
	bucket := os.Args[2]
	key := os.Args[3]

	// Open plugin, and load it into the process.
	p, err := plugin.Open(pluginFilename)
	if err != nil {
		exitErrorf("failed to open plugin, %s, %v", pluginFilename, err)
	}

	// Create a new Credentials value which will source the provider's Retrieve
	// and IsExpired functions from the plugin.
	creds, err := plugincreds.NewCredentials(p)
	if err != nil {
		exitErrorf("failed to load plugin provider, %v", err)
	}

	// Example to configure a Session with the newly created credentials that
	// will be sourced using the plugin's functionality.
	sess := session.Must(session.NewSession(&aws.Config{
		Credentials: creds,
	}))

	// If the region is not available attempt to derive the bucket's region
	// from a query to S3 for the bucket's metadata
	region := aws.StringValue(sess.Config.Region)
	if len(region) == 0 {
		region, err = s3manager.GetBucketRegion(context.Background(), sess, bucket, endpoints.UsEast1RegionID)
		if err != nil {
			exitErrorf("failed to get bucket region, %v", err)
		}
	}

	// Create the S3 service client for the target region
	svc := s3.New(sess, aws.NewConfig().WithRegion(region))

	// Get the object's details
	result, err := svc.HeadObject(&s3.HeadObjectInput{
		Bucket: aws.String(bucket),
		Key:    aws.String(key),
	})
	fmt.Println(result, err)
}