docs: def required_items(element, children, attributes):
      """Check an xml element to include given attributes and children.
  
      :param element: ElementTree element
      :param children: list of XPaths to check
      :param attributes: list of attributes names to check
      :raises NotValidXmlException: if some argument is missing
      :raises NotValidXmlException: if some child is missing
      """
      required_elements(element, *children)
      required_attributes(element, *attributes)