class Kramdown::Converter::Kramdown

def inner(el, opts = {indent: 0})
  @stack.push(el)
  result = +''
  el.children.each_with_index do |inner_el, index|
    options = opts.dup
    options[:index] = index
    options[:prev] = (index == 0 ? nil : el.children[index - 1])
    options[:pprev] = (index <= 1 ? nil : el.children[index - 2])
    options[:next] = (index == el.children.length - 1 ? nil : el.children[index + 1])
    options[:nnext] = (index >= el.children.length - 2 ? nil : el.children[index + 2])
    result << convert(inner_el, options)
  end
  @stack.pop
  result
end