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: subscriptions.go
    path of file: ./repos/golang-samples/container_registry/container_analysis
    
    the code of the file until where you have to start completion: // Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// 
    
func createOccurrenceSubscription(subscriptionID, projectID string) error {
	// subscriptionID := fmt.Sprintf("my-occurrences-subscription")
	ctx := context.Background()
	client, err := pubsub.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("pubsub.NewClient: %w", err)
	}
	defer client.Close()

	// This topic id will automatically receive messages when Occurrences are added or modified
	topicID := "container-analysis-occurrences-v1"
	topic := client.Topic(topicID)
	config := pubsub.SubscriptionConfig{Topic: topic}
	_, err = client.CreateSubscription(ctx, subscriptionID, config)
	return fmt.Errorf("client.CreateSubscription: %w", err)
}