code: function getClosestHeading($, headingsSelector, element) {
    const prevElements = $(element).prevAll();
    for (let i = 0; i < prevElements.length; i += 1) {
      const currentElement = $(prevElements[i]);
      if (currentElement.is(headingsSelector)) {
        return currentElement;
      }
      const childHeadings = currentElement.find(headingsSelector);
      if (childHeadings.length > 0) {
        return childHeadings.last();
      }
    }
    if ($(element).parent().length === 0) {
      return null;
    }
    return getClosestHeading($, headingsSelector, $(element).parent());
  }
docs: Gets the closest heading to an element
  @param $ a Cheerio object
  @param headingsSelector jQuery selector for selecting headings
  @param element to find closest heading