def shift_output_lines(delta)
      return if delta == 0
      @data.each do |m|
        m.output.start_pos.line += delta
        m.output.end_pos.line += delta
      end
    end
def shift_output_lines(delta)
      return if delta == 0
      @data.each do |m|
        m.output.start_pos.line += delta
        m.output.end_pos.line += delta
      end
    end
Shifts all output source ranges forward one or more lines.

 @param delta [Integer] The number of lines to shift the ranges forward.