# File lib/googleauth/user_authorizer.rb, line 227
      def store_credentials user_id, credentials
        json = MultiJson.dump(
          client_id:              credentials.client_id,
          access_token:           credentials.access_token,
          refresh_token:          credentials.refresh_token,
          scope:                  credentials.scope,
          expiration_time_millis: credentials.expires_at.to_i * 1000
        )
        @token_store.store user_id, json
        credentials
      end