code: def add_attributes(self, node_or_edge, xml_obj, data, default):
      # Add attrvalues to node or edge
      attvalues = Element("attvalues")
      if len(data) == 0:
          return data
      mode = "static"
      for k, v in data.items():
          # rename generic multigraph key to avoid any name conflict
          if k == "key":
              k = "networkx_key"
          val_type = type(v)
          if val_type not in self.xml_type:
              raise TypeError(
                  f"attribute value type is not allowed: {val_type}"
              )
          if isinstance(v, list):
              # dynamic data
              for val, start, end in v:
                  val_type = type(val)
                  if start is not None or end is not None:
                      mode = "dynamic"
                      self.alter_graph_mode_timeformat(start)
                      self.alter_graph_mode_timeformat(end)
                      break
              attr_id = self.get_attr_id(
                  str(k),
                  self.xml_type[val_type],
                  node_or_edge,
                  default,
                  mode,
              )
              for val, start, end in v:
                  e = Element("attvalue")
                  e.attrib["for"] = attr_id
                  e.attrib["value"] = str(val)
                  # Handle nan, inf, -inf differently
                  if val_type == float:
                      if e.attrib["value"] == "inf":
                          e.attrib["value"] = "INF"
                      elif e.attrib["value"] == "nan":
                          e.attrib["value"] = "NaN"
                      elif e.attrib["value"] == "-inf":
                          e.attrib["value"] = "-INF"
                  if start is not None:
                      e.attrib["start"] = str(start)
                  if end is not None:
                      e.attrib["end"] = str(end)
                  attvalues.append(e)
          else:
              # static data
              mode = "static"
              attr_id = self.get_attr_id(
                  str(k),
                  self.xml_type[val_type],
                  node_or_edge,
                  default,
                  mode,
              )
              e = Element("attvalue")
              e.attrib["for"] = attr_id
              if isinstance(v, bool):
                  e.attrib["value"] = str(v).lower()
              else:
                  e.attrib["value"] = str(v)
                  # Handle float nan, inf, -inf differently
                  if val_type == float:
                      if e.attrib["value"] == "inf":
                          e.attrib["value"] = "INF"
                      elif e.attrib["value"] == "nan":
                          e.attrib["value"] = "NaN"
                      elif e.attrib["value"] == "-inf":
                          e.attrib["value"] = "-INF"
              attvalues.append(e)
      xml_obj.append(attvalues)
      return 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 6 for calling the GEXFWriter obj's underlying member method code with example usage: obj.add_attributes(node_or_edge, xml_obj, data, default) and returns: data, data