code: function (port, requestedPorts) {
      var self           = this,
          serverInstance = this._getServerInstance(port, requestedPorts);
  
      this.servers.push(serverInstance);
  
      serverInstance.on('readyForTests', function () {
        self._runTestOnServer(serverInstance);
      });
  
      serverInstance.on('done', function () {
        self._incrementDone();
      });
  
      serverInstance.on('testResults', this.reporter.handleTestResults.bind(this.reporter));
  
      serverInstance.on('suiteDone', function (suite) {
        self.finishedSuitesCount++;
        self.finishedSuites.push(suite.data);
      });
    }
docs: Functional._createServerWorker(port, requestedPorts)
  - port (Integer)
  - requestedPorts (Integer)