如何获取所有匹配xpath的项目，这些项目不在viewport中？

// 获取所有匹配XPath的项目
function getElementsByXPath(xpath) {
  const elements = [];
  const iterator = document.evaluate(xpath, document, null, XPathResult.UNORDERED_NODE_ITERATOR_TYPE, null);
  let node;
  
  while (node = iterator.iterateNext()) {
    elements.push(node);
  }
  
  return elements;
}

// 判断元素是否在视口中
function isElementInViewport(element) {
  const rect = element.getBoundingClientRect();
  return (
    rect.top >= 0 &&
    rect.left >= 0 &&
    rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
    rect.right <= (window.innerWidth || document.documentElement.clientWidth)
  );
}

// 获取所有匹配XPath的项目但不在视口中的元素
function getElementsNotInViewport(xpath) {
  const matchedElements = getElementsByXPath(xpath);
  const elementsNotInViewport = [];
  
  for (const element of matchedElements) {
    if (!isElementInViewport(element)) {
      elementsNotInViewport.push(element);
    }
  }
  
  return elementsNotInViewport;
}

// 使用示例
const xpathExpression = "//div[@class='example']";
const elements = getElementsNotInViewport(xpathExpression);
console.log(elements);