parameters: (type_constructor, name, bases, type_kwargs,
                           class_tracker_id, extra)
return_statement: return _lookup_class_or_track(class_tracker_id, skeleton_class)
docstring: Build dynamic class with an empty __dict__ to be filled once memoized
  
      If class_tracker_id is not None, try to lookup an existing class definition
      matching that id. If none is found, track a newly reconstructed class
      definition under that id so that other instances stemming from the same
      class id will also reuse this class definition.
  
      The "extra" variable is meant to be a dict (or None) that can be used for
      forward compatibility shall the need arise.
docstring_summary: Build dynamic class with an empty __dict__ to be filled once memoized
docstring_tokens: Build dynamic class with an empty __dict__ to be filled once memoized
function: def _make_skeleton_class(type_constructor, name, bases, type_kwargs,
                           class_tracker_id, extra):
      """Build dynamic class with an empty __dict__ to be filled once memoized
  
      If class_tracker_id is not None, try to lookup an existing class definition
      matching that id. If none is found, track a newly reconstructed class
      definition under that id so that other instances stemming from the same
      class id will also reuse this class definition.
  
      The "extra" variable is meant to be a dict (or None) that can be used for
      forward compatibility shall the need arise.
      """
      skeleton_class = types.new_class(
          name, bases, {'metaclass': type_constructor},
          lambda ns: ns.update(type_kwargs)
      )
      return _lookup_class_or_track(class_tracker_id, skeleton_class)
function_tokens: def _make_skeleton_class ( type_constructor , name , bases , type_kwargs , class_tracker_id , extra ) : skeleton_class = types . new_class ( name , bases , { 'metaclass' : type_constructor } , lambda ns : ns . update ( type_kwargs ) ) return _lookup_class_or_track ( class_tracker_id , skeleton_class )