How to use the hexo-util.tocObj function in hexo-util

function getToc(content) {
    const toc = {};
    const levels = [0, 0, 0];
    const tocObj = getTocObj(content, { min_depth: 1, max_depth: 6 });
    const minLevel = Math.min(...tocObj.map(item => item.level));
    tocObj.forEach(item => {
        const { text, id } = item;
        const level = item.level - minLevel;

        for (let i = 0; i < levels.length; i++) {
            if (i > level) {
                levels[i] = 0;
            } else if (i < level) {
                if (levels[i] === 0) {
                    // if headings start with a lower level heading, set the former heading index to 1
                    // e.g. h3, h2, h1, h2, h3 => 1.1.1, 1.2, 2, 2.1, 2.1.1
                    levels[i] = 1;
                }
            } else {
                levels[i] += 1;

function tocHelper(str, options = {}) {
  options = Object.assign({
    min_depth: 1,
    max_depth: 6,
    class: 'toc',
    list_number: true
  }, options);

  const data = tocObj(str, { min_depth: options.min_depth, max_depth: options.max_depth });

  if (!data.length) return '';

  const className = options.class;
  const listNumber = options.list_number;

  let result = htmlTag('ol', { class: className });
  const lastNumber = [0, 0, 0, 0, 0, 0];
  let firstLevel = 0;
  let lastLevel = 0;

  for (let i = 0, len = data.length; i < len; i++) {
    const el = data[i];
    const { level, id, text } = el;
    const href = id ? `#${id}` : id;