class Differ::Diff

def same(*str)
  return if str.empty?
  if @raw.last.is_a? String
    @raw.last << sep
  elsif @raw.last.is_a? Change
    if @raw.last.change?
      @raw << sep
    else
      change = @raw.pop
      if change.insert? && @raw.last
        @raw.last << sep if change.insert.sub!(/^#{Regexp.quote(sep)}/, '')
      end
      if change.delete? && @raw.last
        @raw.last << sep if change.delete.sub!(/^#{Regexp.quote(sep)}/, '')
      end
      @raw << change
      @raw.last.insert << sep if @raw.last.insert?
      @raw.last.delete << sep if @raw.last.delete?
      @raw << ''
    end
  else
    @raw << ''
  end
  @raw.last << str.join(sep)
end