class Kramdown::Parser::GFM

def generate_gfm_header_id(text)
  result = text.downcase
  result.gsub!(NON_WORD_RE, '')
  result.tr!(" \t", '-')
  @id_counter[result] += 1
  result << (@id_counter[result] > 0 ? "-#{@id_counter[result]}" : '')
  @options[:auto_id_prefix] + result
end