code: def toosm(self):
          
          node = create_elem('node', {'id': str(self.ident),
                                      'lat': str(self.latitude),
                                      'lon': str(self.longitude)})
          node.set('visible', 'true' if self.visible else 'false')
          if self.user:
              node.set('user', self.user)
          if self.timestamp:
              node.set('timestamp', self.timestamp.isoformat())
          if self.tags:
              for key, value in sorted(self.tags.items()):
                  node.append(create_elem('tag', {'k': key, 'v': value}))
  
          return node
docs: Generate a OSM node element subtree.
  
          Returns:
              etree.Element: OSM node element