def stream_lines(tokens, line_num)
      yield line_start(line_num)

      tokens.each do |token, value|
        yield @inner.span(token, value)
      end

      yield line_end(line_num)
    end
def stream_lines(tokens, line_num)
      yield line_start(line_num)

      tokens.each do |token, value|
        yield @inner.span(token, value)
      end

      yield line_end(line_num)
    end
Formats tokens on the specified line into HTML.

 @param tokens [Array<Rouge::Token>] tokens on the line.
 @param line_nums [Integer] the line number (1-based).
 @yield [String] gives formatted content.