/*
 * call-seq:
 *  new(document)
 *
 * Create a new DocumentFragment element on the +document+
 */
static VALUE new(VALUE klass, VALUE doc)
{
  xmlDocPtr xml_doc;
  Data_Get_Struct(doc, xmlDoc, xml_doc);

  xmlNodePtr node = xmlNewDocFragment(xml_doc->doc);
  if(node->doc->children)
    node->ns = node->doc->children->ns;

  VALUE rb_node = Nokogiri_wrap_xml_node(node);

  if(rb_block_given_p()) rb_yield(rb_node);

  return rb_node;
}