code: func ListMetaFor(obj runtime.Object) (*unversioned.ListMeta, error) {
  	v, err := conversion.EnforcePtr(obj)
  	if err != nil {
  		return nil, err
  	}
  	var meta *unversioned.ListMeta
  	err = runtime.FieldPtr(v, "ListMeta", &meta)
  	return meta, err
  }
docs: // ListMetaFor returns a pointer to a provided object's ListMeta,
  // or an error if the object does not have that pointer.
  // TODO: allow runtime.Unknown to extract this object