code: def add_spells(self, node_or_edge_element, node_or_edge_data):
      spells = node_or_edge_data.pop("spells", False)
      if spells:
          spells_element = Element("spells")
          for start, end in spells:
              e = Element("spell")
              if start is not None:
                  e.attrib["start"] = str(start)
                  self.alter_graph_mode_timeformat(start)
              if end is not None:
                  e.attrib["end"] = str(end)
                  self.alter_graph_mode_timeformat(end)
              spells_element.append(e)
          node_or_edge_element.append(spells_element)
      return node_or_edge_data
  
imports: import itertools
  import time
  from xml.etree.ElementTree import Element, ElementTree, SubElement, register_namespace, tostring
  import networkx
  from networkx.utils import open_file
label_desc: Use image node_id 11 for calling the GEXFWriter obj's underlying member method code with example usage: obj.add_spells(node_or_edge_element, node_or_edge_data) and returns: node_or_edge_data