@JeffryBooher This seems ok. Let me give a try. Just confirming, after implementing a new command `FILE_CLOSE_DOCUMENT_LIST`, `handleFileCloseAll` will look like this.

    function handleFileCloseAll(commandData) {
          var  promptOnly = commandData && commandData.promptOnly;

          CommandManager.execute(Commands.FILE_CLOSE_DOCUMENT_LIST, 
          {promptOnly: promptOnly , docList: DocumentManager.getWorkingSet()});
     }

Am i correct?