class Kramdown::Parser::Kramdown

def parse_link_definition
  return false if @src[3].to_s =~ /[ \t]+["']/
  @src.pos += @src.matched_size
  link_id, link_url, link_title = normalize_link_id(@src[1]), @src[2] || @src[3], @src[5]
  if @link_defs[link_id]
    warning("Duplicate link ID '#{link_id}' on line #{@src.current_line_number} - overwriting")
  end
  @tree.children << new_block_el(:eob, :link_def)
  @link_defs[link_id] = [link_url, link_title, @tree.children.last]
  true
end