code: def author_contributions(soup, fntype_filter):
      
  
      author_contributions_section = extract_nodes(soup, "fn-group", attr="content-type", value="author-contribution")
      if not author_contributions_section:
          return None
      fn = extract_nodes(first(author_contributions_section), "fn")
      cons = footnotes(fn, fntype_filter)
  
      return cons
docs: Find the fn tags included in the competing interest