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: plugins.go
    path of file: ./repos/kubernetes/vendor/sigs.k8s.io/kustomize/api/konfig
    
    the code of the file until where you have to start completion: // Copyright 2019 The Kubernetes Authors.
// SPDX-License-Identifier: Apache-2.0

package konfig

import (
	"os"
	"path/filepath"
	"runtime"

	"sigs.k8s.io/kustomize/api/types"
	"sigs.k8s.io/kustomize/kyaml/filesys"
)

const (
	// Symbol that must be used inside Go plugins.
	PluginSymbol = "KustomizePlugin"

	// Name of environment variable used to set AbsPluginHome.
	// See that variable for an explanation.
	KustomizePluginHomeEnv = "KUSTOMIZE_PLUGIN_HOME"

	// Relative path below XDG_CONFIG_HOME/kustomize to find plugins.
	// e.g. AbsPluginHome = XDG_CONFIG_HOME/kustomize/plugin
	RelPluginHome = "plugin"

	// Location of builtin plugins below AbsPluginHome.
	BuiltinPluginPackage = "builtin"

	// The value of kubernetes ApiVersion to use in configuration
	// files for builtin plugins.
	// The value for non-b
    
func DefaultAbsPluginHome(fSys filesys.FileSystem) (string, error) {
	return FirstDirThatExistsElseError(
		"plugin root", fSys, []NotedFunc{
			{
				Note: "homed in $" + KustomizePluginHomeEnv,
				F: func() string {
					return os.Getenv(KustomizePluginHomeEnv)
				},
			},
			{
				Note: "homed in $" + XdgConfigHomeEnv,
				F: func() string {
					if root := os.Getenv(XdgConfigHomeEnv); root != "" {
						return filepath.Join(root, ProgramName, RelPluginHome)
					}
					// do not look in "kustomize/plugin" if XdgConfigHomeEnv is unset
					return ""
				},
			},
			{
				Note: "homed in default value of $" + XdgConfigHomeEnv,
				F: func() string {
					return filepath.Join(
						HomeDir(), XdgConfigHomeEnvDefault,
						ProgramName, RelPluginHome)
				},
			},
			{
				Note: "homed in home directory",
				F: func() string {
					return filepath.Join(
						HomeDir(), ProgramName, RelPluginHome)
				},
			},
		})
}