code: function FindFreePortSync(options = {}) {
      this.defaultOptions = {
          // port start for scan
          start: 1,
          // port end for scan
          end: 65534,
          // ports number for scan
          num: 1,
          // specify ip for scan
          ip: '0.0.0.0|127.0.0.1',
          // for inner usage, some platforms like darkwin shows commom address 0.0.0.0:10000 as *.10000
          _ipSpecial: '\\*|127.0.0.1',
          // scan this port
          port: null
      };
  
      this.msg = {
          error: 'Cannot find free port'
      }
  
      this.adjustOptions(options);
  }
docs: Finding free port synchronously
  @param {Object} options [description]