docs: function getAuthClient() {
      return new Promise((resolve, reject) => {
          const redirectUrl = constants.REDIRECT_URL;
          const port = constants.REDIRECT_PORT;
          const configFilepath = path.join(constants.GLOBAL_DIR, constants.GLOBAL_CONFIG);
  
          let clientId = constants.CLIENT_ID;
          let clientSecret = null;
          let custom = false;
  
          // Parse config file
          try {
              const config = fs.readJsonSync(configFilepath, 'utf8');
              if (config.client) {
                  clientSecret = config.client.secret;
                  clientId = config.client.id;
                  custom = true;
              }
          } catch (err) {
              reject(err);
              return;
          }
  
          const client = new google.auth.OAuth2(clientId, clientSecret, `${redirectUrl}:${port}`);
  
          resolve({
              client,
              custom,
          });
      });
  }