You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: strategy.go
    path of file: ./repos/gardener/pkg/apiserver/registry/core/controllerinstallation
    
    the code of the file until where you have to start completion: // Copyright 2018 SAP SE or an SAP affiliate company. All rights reserved. This file is licensed under the Apache Software License, v. 2 except as noted otherwise in the LICENSE file
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License
    
func ToSelectableFields(controllerInstallation *core.ControllerInstallation) fields.Set {
	// The purpose of allocation with a given number of elements is to reduce
	// amount of allocations needed to create the fields.Set. If you add any
	// field here or the number of object-meta related fields changes, this should
	// be adjusted.
	controllerInstallationSpecificFieldsSet := make(fields.Set, 3)
	controllerInstallationSpecificFieldsSet[core.RegistrationRefName] = controllerInstallation.Spec.RegistrationRef.Name
	controllerInstallationSpecificFieldsSet[core.SeedRefName] = controllerInstallation.Spec.SeedRef.Name
	return generic.AddObjectMetaFieldsSet(controllerInstallationSpecificFieldsSet, &controllerInstallation.ObjectMeta, false)
}