# File lib/Getopt/Declare.rb, line 41
  def expand_tabs!( tabstop = 8 )
    while self.sub!(/(^|\n)([^\t\n]*)(\t+)/sex) { |f|
        val = ( tabstop * "#$3".length() - ("#$2".length() % tabstop) )
        "#$1#$2" + (" " * val)
      }
    end
    self
  end