class Sanitize

def document(html)

{#fragment} instead.
error will be raised. If this is undesirable, you should probably use
When sanitizing a document, the `` element must be whitelisted or an

Returns a sanitized copy of the given _html_ document. 
def document(html)
  return '' unless html
  doc = Nokogiri::HTML5.parse(preprocess(html))
  node!(doc)
  to_html(doc)
end