if (labelText == null || labelText.charAt(index) != mnemonicKey) index = -1;
if (text == null || text.charAt(newIndex) != displayedMnemonic) newIndex = -1;
  public void setDisplayedMnemonicIndex(int index)                                 throws IllegalArgumentException  {    if (index < -1 || labelText != null && index >= labelText.length())      throw new IllegalArgumentException();          if (labelText == null || labelText.charAt(index) != mnemonicKey)      index = -1;          if (index != underlinedChar)    {      int oldIndex = underlinedChar;        underlinedChar = index;      firePropertyChange(DISPLAYED_MNEMONIC_INDEX_CHANGED_PROPERTY,                         oldIndex, underlinedChar);    }  }