def authorize
      client_id = Google::Auth::ClientId.from_file(CLIENT_SECRETS_PATH)
      token_store = Google::Auth::Stores::FileTokenStore.new(file: CREDENTIALS_PATH)
      authorizer = Google::Auth::UserAuthorizer.new(client_id, SCOPE, token_store)
      user_id = 'default'
      credentials = authorizer.get_credentials(user_id)

      if credentials.nil?
        url = authorizer.get_authorization_url(base_url: OOB_URI)

        puts 'Open the following URL in the browser and enter the ' \
          "resulting code after authorization:\n" + url
        code = STDIN.gets

        credentials = authorizer.get_and_store_credentials_from_code(
          user_id: user_id, code: code, base_url: OOB_URI
        )
      end

      credentials
    end
def authorize
      client_id = Google::Auth::ClientId.from_file(CLIENT_SECRETS_PATH)
      token_store = Google::Auth::Stores::FileTokenStore.new(file: CREDENTIALS_PATH)
      authorizer = Google::Auth::UserAuthorizer.new(client_id, SCOPE, token_store)
      user_id = 'default'
      credentials = authorizer.get_credentials(user_id)

      if credentials.nil?
        url = authorizer.get_authorization_url(base_url: OOB_URI)

        puts 'Open the following URL in the browser and enter the ' \
          "resulting code after authorization:\n" + url
        code = STDIN.gets

        credentials = authorizer.get_and_store_credentials_from_code(
          user_id: user_id, code: code, base_url: OOB_URI
        )
      end

      credentials
    end
Ensure valid credentials, either by restoring from the saved credentials
 files or intitiating an OAuth2 authorization. If authorization is required,
 the user's default browser will be launched to approve the request.

 @return [Google::Auth::UserRefreshCredentials] OAuth2 credentials