docs: public DirectoryBrowserSupport doWs( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException, InterruptedException {
          checkPermission(Item.WORKSPACE);
          FilePath ws = getSomeWorkspace();
          if ((ws == null) || (!ws.exists())) {
              // if there's no workspace, report a nice error message
              // Would be good if when asked for *plain*, do something else!
              // (E.g. return 404, or send empty doc.)
              // Not critical; client can just check if content type is not text/plain,
              // which also serves to detect old versions of Hudson.
              req.getView(this,"noWorkspace.jelly").forward(req,rsp);
              return null;
          } else {
              Computer c = ws.toComputer();
              String title;
              if (c == null) {
                  title = Messages.AbstractProject_WorkspaceTitle(getDisplayName());
              } else {
                  title = Messages.AbstractProject_WorkspaceTitleOnComputer(getDisplayName(), c.getDisplayName());
              }
              return new DirectoryBrowserSupport(this, ws, title, "folder.png", true);
          }
      }