def pull_to_start(name)
      loop do
        res = pull
        raise NotFoundError if res.event_type == :end_document
        next if res.start_element? && res[0] == name.to_s
      end
    end
def pull_to_start(name)
      loop do
        res = pull
        raise NotFoundError if res.event_type == :end_document
        next if res.start_element? && res[0] == name.to_s
      end
    end
Pull events until the start of an element of tag name +name+ is
 reached.