code: func (f *FieldManager) stripFields(managed fieldpath.ManagedFields, manager string) fieldpath.ManagedFields {
  	vs, ok := managed[manager]
  	if ok {
  		if vs == nil {
  			panic(fmt.Sprintf("Found unexpected nil manager which should never happen: %s", manager))
  		}
  		vs.Set = vs.Set.Difference(stripSet)
  		if vs.Set.Empty() {
  			delete(managed, manager)
  		}
  	}
  
  	return managed
  }
docs: // stripFields removes a predefined set of paths found in typed from managed and returns the updated ManagedFields