code: function _getBioContent (el, importer) {
    let $$ = el.createElement.bind(el.getOwnerDocument())
    let bioEl = findChild(el, 'bio')
  
    // If there is no bio element we should provide it
    if (!bioEl) {
      bioEl = $$('bio')
    }
  
    // TODO: this code looks similar to what we have in abstract or and caption
    // drop everything other than 'p' from bio
    retainChildren(bioEl, 'p')
    // there must be at least one paragraph
    if (!bioEl.find('p')) {
      bioEl.append($$('p'))
    }
  
    return bioEl.children.map(child => importer.convertElement(child).id)
  }
docs: ATTENTION: bio is not a specific node anymore, just a collection of paragraphs