code: function(safe) {
        // pagehide event hack above
        if (this.unloaded) {
          this.win.document.designMode = "off";
          this.win.document.designMode = "on";
          this.unloaded = false;
        }
  
        if (internetExplorer) {
          this.container.createTextRange().execCommand("unlink");
          this.selectionSnapshot = select.getBookmark(this.container);
        }
  
        var activity = this.options.cursorActivity;
        if (!safe || activity) {
          var cursor = select.selectionTopNode(this.container, false);
          if (cursor === false || !this.container.firstChild) return;
          cursor = cursor || this.container.firstChild;
          if (activity) activity(cursor);
          if (!safe) {
            this.scheduleHighlight();
            this.addDirtyNode(cursor);
          }
        }
      }
docs: Find the node that the cursor is in, mark it as dirty, and make sure a highlight pass is scheduled.