code: function stopRelay(cb) {
          var self = this;
  
          if (!this.control && !this.process) {
              return cb();
          }
  
          this.control.signalShutdown(function (err) {
              if (err) {
                  return cb(err);
              }
              self.process.on('exit', function () {
                  /**
                   * @callback TorRelay~stopCallback
                   * @param {null| error} error - Error if there was one
                   */
                  return cb();
              });
          });
          return this;
      }
docs: Stop tor
  @param {TorRelay~stopCallback} cb - Stop callback function
  @returns {*}