class Kramdown::Parser::Kramdown

def update_tree(element)

(resets +@tree+, +@src+ and the +@stack+) and by updating the attributes from the IALs.
Update the tree by parsing all :raw_text elements with the span level parser 
def update_tree(element)
  element.children.map! do |child|
    if child.type == :raw_text
      @stack, @tree, @text_type = [], nil, :text
      @src = StringScanner.new(child.value)
      parse_spans(child)
      child.children
    else
      update_tree(child)
      update_attr_with_ial(child.options[:attr] ||= {}, child.options[:ial]) if child.options[:ial]
      child
    end
  end.flatten!
end