code: function _handleRelatedDocumentDeleted(url) {
          var liveDoc = _relatedDocuments[url];
          if (liveDoc) {
              delete _relatedDocuments[url];
          }
  
          if (_server) {
              _server.remove(liveDoc);
          }
          _closeDocument(liveDoc);
      }
docs: Removes the given CSS/JSDocument from _relatedDocuments. Signals that the
  given file is no longer associated with the HTML document that is live (e.g.
  if the related file has been deleted on disk).
  @param {string} url Absolute URL of the related document