code: function findInvalidAncestorForTag(tag, ancestorInfo) {
      switch (tag) {
        case 'address':
        case 'article':
        case 'aside':
        case 'blockquote':
        case 'center':
        case 'details':
        case 'dialog':
        case 'dir':
        case 'div':
        case 'dl':
        case 'fieldset':
        case 'figcaption':
        case 'figure':
        case 'footer':
        case 'header':
        case 'hgroup':
        case 'main':
        case 'menu':
        case 'nav':
        case 'ol':
        case 'p':
        case 'section':
        case 'summary':
        case 'ul':
        case 'pre':
        case 'listing':
        case 'table':
        case 'hr':
        case 'xmp':
        case 'h1':
        case 'h2':
        case 'h3':
        case 'h4':
        case 'h5':
        case 'h6':
          return ancestorInfo.pTagInButtonScope;
  
        case 'form':
          return ancestorInfo.formTag || ancestorInfo.pTagInButtonScope;
  
        case 'li':
          return ancestorInfo.listItemTagAutoclosing;
  
        case 'dd':
        case 'dt':
          return ancestorInfo.dlItemTagAutoclosing;
  
        case 'button':
          return ancestorInfo.buttonTagInScope;
  
        case 'a':
          // Spec says something about storing a list of markers, but it sounds
          // equivalent to this check.
          return ancestorInfo.aTagInScope;
  
        case 'nobr':
          return ancestorInfo.nobrTagInScope;
      }
  
      return null;
    }
docs: Returns whether