code: function init(domainManager) {
      if (!domainManager.hasDomain("fileWatcher")) {
          domainManager.registerDomain("fileWatcher", {major: 0, minor: 1});
      }
  
      domainManager.registerCommand(
          "fileWatcher",
          "watchPath",
          watcherManager.watchPath,
          false,
          "Start watching a file or directory",
          [{
              name: "path",
              type: "string",
              description: "absolute filesystem path of the file or directory to watch"
          }, {
              name: "ignored",
              type: "array",
              description: "list of path to ignore"
          }]
      );
      domainManager.registerCommand(
          "fileWatcher",
          "unwatchPath",
          watcherManager.unwatchPath,
          false,
          "Stop watching a single file or a directory and it's descendants",
          [{
              name: "path",
              type: "string",
              description: "absolute filesystem path of the file or directory to unwatch"
          }]
      );
      domainManager.registerCommand(
          "fileWatcher",
          "unwatchAll",
          watcherManager.unwatchAll,
          false,
          "Stop watching all files and directories"
      );
      domainManager.registerEvent(
          "fileWatcher",
          "change",
          [
              {name: "event", type: "string"},
              {name: "parentDirPath", type: "string"},
              {name: "entryName", type: "string"},
              {name: "statsObj", type: "object"}
          ]
      );
  
      watcherManager.setDomainManager(domainManager);
      watcherManager.setWatcherImpl(watcherImpl);
  
  }
docs: Initialize the "fileWatcher" domain.
  The fileWatcher domain handles watching and un-watching directories.