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: http.go
    path of file: ./repos/juju/api/http
    
    the code of the file until where you have to start completion: // Copyright 2022 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.

package http

import (
	"context"
	"io"
	"net/http"
	"net/url"

	"github.com/juju/errors"

	"github.com/juju/juju/a
    
func openBlobReader(ctx context.Context, httpClient HTTPDoer, endpoint string, args url.Values) (io.ReadCloser, error) {
	apiURL, err := url.Parse(endpoint)
	if err != nil {
		return nil, errors.Trace(err)
	}
	apiURL.RawQuery = args.Encode()
	req, err := http.NewRequest(http.MethodGet, apiURL.String(), nil)
	if err != nil {
		return nil, errors.Annotate(err, "cannot create HTTP request")
	}

	var resp *http.Response
	if err := httpClient.Do(ctx, req, &resp); err != nil {
		return nil, errors.Trace(err)
	}
	return resp.Body, nil
}