if (toAppend != null && toAppend.length() > 0) revalidate();
  public void append(String toAppend)  {      try	  {	      getDocument().insertString(getText().length(), toAppend, null);	  }      catch (BadLocationException exception)	  {	      /* This shouldn't happen in theory -- but, if it does...  */	      throw new RuntimeException("Unexpected exception occurred.", exception);	  }  }