docstr: Appends attribute data.
docstr_tok: ["Appends","attribute","data","."]
code: def add_attributes(self, scope, xml_obj, data, default):
      """Appends attribute data."""
      for k, v in data.items():
          data_element = self.add_data(
              str(k),
              self.attr_type(str(k), scope, v),
              str(v),
              scope,
              default.get(k),
          )
          xml_obj.append(data_element)
  
imports: import warnings
  from collections import defaultdict
  import networkx
  from networkx.utils import open_file
label_desc: Use image node_id 3 for calling the GraphMLWriterLxml obj's underlying member method code with example usage: obj.add_attributes(scope, xml_obj, data, default) without return types