class Kramdown::Converter::Html

def convert(el, indent = -2)

Convert the element tree +el+, setting the indentation level to +indent+.
def convert(el, indent = -2)
  result = ''
  el.children.each do |inner_el|
    result << convert(inner_el, indent + 2)
  end
  send("convert_#{el.type}", el, result, indent)
end