# File lib/differ/diff.rb, line 50
    def insert(*str)
      return if str.empty?
      if @raw.last.is_a? Change
        change = @raw.pop
        if change.delete? && @raw.last
          @raw.last << sep if change.delete.sub!(/^#{Regexp.quote(sep)}/, '')
        end
        change.insert << sep if change.insert?
      else
        change = Change.new(:insert => @raw.empty? ? '' : sep)
      end

      @raw << change
      @raw.last.insert << str.join(sep)
    end