code: def __from_xml(self, xmlnode):
          
  
          self.__logger.debug("Converting jabber:iq:register element from XML")
          if xmlnode.type!="element":
              raise ValueError("XML node is not a jabber:iq:register element (not an element)")
          ns=get_node_ns_uri(xmlnode)
          if ns and ns!=REGISTER_NS or xmlnode.name!="query":
              raise ValueError("XML node is not a jabber:iq:register element")
  
          for element in xml_element_iter(xmlnode.children):
              ns = get_node_ns_uri(element)
              if ns == DATAFORM_NS and element.name == "x" and not self.form:
                  self.form = Form(element)
              elif ns != REGISTER_NS:
                  continue
              name = element.name
              if name == "instructions" and not self.instructions:
                  self.instructions = from_utf8(element.getContent())
              elif name == "registered":
                  self.registered = True
              elif name == "remove":
                  self.remove = True
              elif name in legacy_fields and not getattr(self, name):
                  value = from_utf8(element.getContent())
                  if value is None:
                      value = u""
                  self.__logger.debug(u"Setting legacy field %r to %r" % (name, value))
                  setattr(self, name, value)
docs: Initialize `Register` from an XML node.
  
          :Parameters:
              - `xmlnode`: the jabber:x:register XML element.
          :Types:
              - `xmlnode`: `libxml2.xmlNode`