def indent( mod = nil )
      #p [ self.id, level, mod, :INDENT ]
      if level <= 0
        mod ||= 0
      else
        mod ||= options(:Indent)
        mod += ( level - 1 ) * options(:Indent)
      end
      return " " * mod
    end
def indent( mod = nil )
      #p [ self.id, level, mod, :INDENT ]
      if level <= 0
        mod ||= 0
      else
        mod ||= options(:Indent)
        mod += ( level - 1 ) * options(:Indent)
      end
      return " " * mod
    end
Write a current indent