/*
 * call-seq:
 *  prefix
 *
 * Get the element content namespace +prefix+.
 */
static VALUE get_prefix(VALUE self)
{
  xmlElementContentPtr elem;
  Data_Get_Struct(self, xmlElementContent, elem);

  if(!elem->prefix) return Qnil;

  return NOKOGIRI_STR_NEW2(elem->prefix);
}