code: def _get_template(self, root=None, **metadata_defaults):
          
  
          if root is None:
              if self._data_map is None:
                  self._init_data_map()
  
              root = self._xml_root = self._data_map['_root']
  
          template_tree = self._xml_tree = create_element_tree(root)
  
          for prop, val in iteritems(metadata_defaults):
              path = self._data_map.get(prop)
              if path and val:
                  setattr(self, prop, val)
                  update_property(template_tree, None, path, prop, val)
  
          return template_tree
docs: Iterate over items metadata_defaults {prop: val, ...} to populate template