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: pinboard.go
    path of file: ./repos/v2/internal/integration/pinboard
    
    the code of the file until where you have to start completion: // SPDX-FileCopyrightText: Copyright The Miniflux Authors. All rights reserved.
// SPDX-License-Identifier: Apache-2.0

package pinboard // import "miniflux.app/v2/internal/integration/pinboard"

import (
	"fmt"
	"net/http"
	"net/url"
	"time"

	"miniflux.app/v2/internal/version"
)

const defaultClientTimeout = 10 * time.Second

type Client struct {
	authToken string
}

func NewClient(authToken string) *Client {
	return &Client{authToken: authToken}
}

func (c *Client) CreateBookmark(entryURL, entryTitle, pinboardTags string, markAsUnread bool) error {
	if c.authToken =
    
func (c *Client) CreateBookmark(entryURL, entryTitle, pinboardTags string, markAsUnread bool) error {
	if c.authToken == "" {
		return fmt.Errorf("pinboard: missing auth token")
	}

	toRead := "no"
	if markAsUnread {
		toRead = "yes"
	}

	values := url.Values{}
	values.Add("auth_token", c.authToken)
	values.Add("url", entryURL)
	values.Add("description", entryTitle)
	values.Add("tags", pinboardTags)
	values.Add("toread", toRead)

	apiEndpoint := "https://api.pinboard.in/v1/posts/add?" + values.Encode()
	request, err := http.NewRequest(http.MethodGet, apiEndpoint, nil)
	if err != nil {
		return fmt.Errorf("pinboard: unable to create request: %v", err)
	}

	request.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	request.Header.Set("User-Agent", "Miniflux/"+version.Version)

	httpClient := &http.Client{Timeout: defaultClientTimeout}
	response, err := httpClient.Do(request)
	if err != nil {
		return fmt.Errorf("pinboard: unable to send request: %v", err)
	}
	defer response.Body.Close()

	if response.StatusCode >= 400 {
		return fmt.Errorf("pinboard: unable to create a bookmark: url=%s status=%d", apiEndpoint, response.StatusCode)
	}

	return nil
}