code: def add_slices(self, node_or_edge_element, node_or_edge_data):
      slices = node_or_edge_data.pop("slices", False)
      if slices:
          slices_element = Element("slices")
          for start, end in slices:
              e = Element("slice", start=str(start), end=str(end))
              slices_element.append(e)
          node_or_edge_element.append(slices_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 10 for calling the GEXFWriter obj's underlying member method code with example usage: obj.add_slices(node_or_edge_element, node_or_edge_data) and returns: node_or_edge_data