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: index_retrieve.go
    path of file: ./repos/langchaingo/vectorstores/azureaisearch
    
    the code of the file until where you have to start completion: package azureaisearch

import (
	"context"
	"fmt"
	"net/http"
)

// RetrieveIndex send a request to azure AI search Rest API for retrieving an index, helper function.
func (s *Store) RetrieveIndex(ctx cont
    
func (s *Store) RetrieveIndex(ctx context.Context, indexName string, output *map[string]interface{}) error {
	URL := fmt.Sprintf("%s/indexes/%s?api-version=2023-11-01", s.azureAISearchEndpoint, indexName)
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, URL, nil)
	if err != nil {
		return fmt.Errorf("err setting request for index retrieving: %w", err)
	}

	req.Header.Add("Content-Type", "application/json")
	if s.azureAISearchAPIKey != "" {
		req.Header.Add("api-key", s.azureAISearchAPIKey)
	}

	return s.httpDefaultSend(req, "search documents on azure ai search", output)
}