code: function (args, callback) {
          if (ternserver && typeof args.file === 'string') {
            ternserver.delFile(args.file);
            callback({request: 'delFile'}); //$NON-NLS-1$
          } else {
            callback({request: 'delFile', message: i18nUtil.formatMessage(Messages['failedDeleteRequest'], args.file)}); //$NON-NLS-1$
          }
        }
docs: /* delFile message handler