@Override
 public void actionPerformed(AnActionEvent e) {
   Project project = e.getProject();
   if (project == null) {
     return;
   }
   for (StudyActionListener listener : Extensions.getExtensions(StudyActionListener.EP_NAME)) {
     listener.beforeCheck(e);
   }
   final AnswerPlaceholder answerPlaceholder = getAnswerPlaceholder(e);
   if (answerPlaceholder == null) {
     return;
   }
   StudyEditor studyEditor = StudyUtils.getSelectedStudyEditor(project);
   final StudyState studyState = new StudyState(studyEditor);
   if (answerPlaceholder.getTaskFile().getTask().hasSubtasks()) {
     StudySubtaskUtils.refreshPlaceholder(studyState.getEditor(), answerPlaceholder);
     return;
   }
   Document patternDocument =
       StudyUtils.getPatternDocument(
           answerPlaceholder.getTaskFile(), studyState.getVirtualFile().getName());
   if (patternDocument == null) {
     return;
   }
   AnswerPlaceholder.MyInitialState initialState = answerPlaceholder.getInitialState();
   int startOffset = initialState.getOffset();
   final String text =
       patternDocument.getText(new TextRange(startOffset, startOffset + initialState.getLength()));
   CommandProcessor.getInstance()
       .executeCommand(
           project,
           () ->
               ApplicationManager.getApplication()
                   .runWriteAction(
                       () -> {
                         Document document = studyState.getEditor().getDocument();
                         int offset = answerPlaceholder.getOffset();
                         document.deleteString(offset, offset + answerPlaceholder.getRealLength());
                         document.insertString(offset, text);
                       }),
           NAME,
           null);
 }
  public static void navigateToFailedPlaceholder(
      @NotNull final StudyState studyState,
      @NotNull final Task task,
      @NotNull final VirtualFile taskDir,
      @NotNull final Project project) {
    TaskFile selectedTaskFile = studyState.getTaskFile();
    Editor editor = studyState.getEditor();
    TaskFile taskFileToNavigate = selectedTaskFile;
    VirtualFile fileToNavigate = studyState.getVirtualFile();
    final StudyTaskManager taskManager = StudyTaskManager.getInstance(project);
    if (!taskManager.hasFailedAnswerPlaceholders(selectedTaskFile)) {
      for (Map.Entry<String, TaskFile> entry : task.getTaskFiles().entrySet()) {
        String name = entry.getKey();
        TaskFile taskFile = entry.getValue();
        if (taskManager.hasFailedAnswerPlaceholders(taskFile)) {
          taskFileToNavigate = taskFile;
          VirtualFile virtualFile = taskDir.findChild(name);
          if (virtualFile == null) {
            continue;
          }
          FileEditor fileEditor =
              FileEditorManager.getInstance(project).getSelectedEditor(virtualFile);
          if (fileEditor instanceof StudyEditor) {
            StudyEditor studyEditor = (StudyEditor) fileEditor;
            editor = studyEditor.getEditor();
          }
          fileToNavigate = virtualFile;
          break;
        }
      }
    }
    if (fileToNavigate != null) {
      FileEditorManager.getInstance(project).openFile(fileToNavigate, true);
    }
    final Editor editorToNavigate = editor;
    ApplicationManager.getApplication()
        .invokeLater(
            () ->
                IdeFocusManager.getInstance(project)
                    .requestFocus(editorToNavigate.getContentComponent(), true));

    StudyNavigator.navigateToFirstFailedAnswerPlaceholder(editor, taskFileToNavigate);
  }