class Kramdown::Parser::GFM

def initialize(source, options)
  super
  @span_parsers.delete(:line_break) if @options[:hard_wrap]
  if @options[:gfm_quirks].include?(:paragraph_end)
    atx_header_parser = :atx_header_gfm_quirk
    @paragraph_end = self.class::PARAGRAPH_END_GFM
  else
    atx_header_parser = :atx_header_gfm
    @paragraph_end = self.class::PARAGRAPH_END
  end
  {:codeblock_fenced => :codeblock_fenced_gfm,
    :atx_header => atx_header_parser}.each do |current, replacement|
    i = @block_parsers.index(current)
    @block_parsers.delete(current)
    @block_parsers.insert(i, replacement)
  end
  i = @span_parsers.index(:escaped_chars)
  @span_parsers[i] = :escaped_chars_gfm if i
  @span_parsers << :strikethrough_gfm
end