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: file.go
    path of file: ./repos/bud/package/genfs
    
    the code of the file until where you have to start completion: package genfs

import (
	"io/fs"
	"path"

	"github.com/livebud/bud/package/virtual"
)

type File struct {
	Data []byte

	// Target and path are the same when called within GenerateFile, but not
	// always the same when called within ServeFile
	path   string
	target string
}

func (f *File) Target() string {
	return f.target
}

func (f *File) Relative() string {
	return relativePath(f.path, f.target)
}

func (f *File) Path() string {
	return f.path
}

// Ext 
    
func (f *fileGenerator) Generate(target string) (fs.File, error) {
	if target != f.path {
		return nil, formatError(fs.ErrNotExist, "%q path doesn't match %q target", f.path, target)
	}
	if file, err := f.cache.Get(target); err == nil {
		return virtual.Open(file), nil
	}
	file := &File{nil, f.path, target}
	scoped := &scopedFS{f.cache, f.genfs, target}
	if err := f.fn(scoped, file); err != nil {
		return nil, err
	}
	vfile := &virtual.File{
		Path: target,
		Mode: fs.FileMode(0),
		Data: file.Data,
	}
	if err := f.cache.Set(target, vfile); err != nil {
		return nil, err
	}
	return virtual.Open(vfile), nil
}