public void clearAllParagraphOutput() {
    for (Paragraph p : paragraphs) {
      p.setReturn(null, null);
    }
  }
@Test
  void clearAllParagraphOutputTest() throws InterpreterNotFoundException {

    Note note = new Note("test", "", interpreterFactory, interpreterSettingManager,
        paragraphJobListener, credentials, noteEventListener, zConf, noteParser);
    Paragraph p1 = note.addNewParagraph(AuthenticationInfo.ANONYMOUS);
    InterpreterResult result = new InterpreterResult(InterpreterResult.Code.SUCCESS, InterpreterResult.Type.TEXT, "result");
    p1.setResult(result);

    Paragraph p2 = note.addNewParagraph(AuthenticationInfo.ANONYMOUS);
    p2.setReturn(result, new Throwable());

    note.clearAllParagraphOutput();

    assertNull(p1.getReturn());
    assertNull(p2.getReturn());
  }