docs: def _parse_price(html_chunk):
      """
      Parse price of the book.
  
      Args:
          html_chunk (obj): HTMLElement containing slice of the page with details.
  
      Returns:
          str/None: Price as string with currency or None if not found.
      """
      price = get_first_content(
          html_chunk.find("div", {"class": "prices"})
      )
  
      if not price:
          return None
  
      # it is always in format Cena:\n150kč
      price = dhtmlparser.removeTags(price)
      price = price.split("\n")[-1]
  
      return price