void (@NotNull ContentManagerEvent event) { final Content eventContent = event.getContent(); if (!eventContent.equals(myContent)) { return; } myMessageView.getContentManager().removeContentManagerListener(this); NewErrorTreeViewPanel errorTreeView = eventContent.getUserData(myKey); if (errorTreeView != null) { Disposer.dispose(errorTreeView); } eventContent.putUserData(myKey, null); }