[Selenium]对于某些对话框即有可能弹出来，也有可能不弹出来，这种应该怎么处理呢？

界面上如果有一个对话框可能弹出来，也可能不弹出，我们都要认为是正常，应该怎么处理呢？

/**
	 * check if release notes dialog present
	 * @author j
	 */
	public boolean isReleaseNotesDialogPresent(){
		try{
			new WebDriverWait(driver, 30).until(ExpectedConditions.presenceOfElementLocated(By.cssSelector("div#releaseNotes")));
			return true;
		}
		catch(Exception e){
			logger.info("There's no release notes dialog pop up");
			return false;
		}
	}

	/**
	 * check if release notes dialog present,if yes,close release notes dialog by click close button
	 * @author j
	 */
	public void closeReleaseNotesDialog(){
		boolean isDialogPresent=isReleaseNotesDialogPresent();
		if(isDialogPresent==true){
			SeleniumUtil.waitForElementPresent(driver, By.cssSelector("input#btnClose")).click();
		}
	}