code: function getWillowProgDataPaths () {
      if (!process.env.systemdrive) {
          // running on linux/osx?
          return [];
      }
      var instancesRoot = path.join(process.env.systemdrive, 'ProgramData/Microsoft/VisualStudio/Packages/_Instances');
      if (!shell.test('-d', instancesRoot)) {
          // can't seem to find VS instances dir, return empty result
          return [];
      }
  
      return fs.readdirSync(instancesRoot).map(function (file) {
          var instanceDir = path.join(instancesRoot, file);
          if (shell.test('-d', instanceDir)) {
              return instanceDir;
          }
      }).filter(function (progDataPath) {
          // make sure state.json exists
          return shell.test('-e', path.join(progDataPath, 'state.json'));
      });
  }
docs: Lists all VS 2017+ instances dirs in ProgramData
  
  @return {String[]} List of paths to all VS2017+ instances