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: walk.go
    path of file: ./repos/alist/internal/fs
    
    the code of the file until where you have to start completion: package fs

import (
	"context"
	"path"
	"path/filepath"

	"github.com/alist-org/alist/v3/internal/model"
	"github.com/alist-org/alist/v3/internal/op"
)

// WalkFS traverses filesystem fs starting at name up to depth levels.
//
// WalkFS will stop when current depth > `depth`. For each visited node,
// WalkFS calls walkFn. If a visited file system node is a directory and
// walkFn returns path.SkipDir, walkFS will skip traversal of this node.
func WalkFS(ctx context.Context, depth int, name string, info model.Obj, walkFn func(reqPath string, info model.Obj) error) error {
	// This imp
    
func WalkFS(ctx context.Context, depth int, name string, info model.Obj, walkFn func(reqPath string, info model.Obj) error) error {
	// This implementation is based on Walk's code in the standard path/path package.
	walkFnErr := walkFn(name, info)
	if walkFnErr != nil {
		if info.IsDir() && walkFnErr == filepath.SkipDir {
			return nil
		}
		return walkFnErr
	}
	if !info.IsDir() || depth == 0 {
		return nil
	}
	meta, _ := op.GetNearestMeta(name)
	// Read directory names.
	objs, err := List(context.WithValue(ctx, "meta", meta), name, &ListArgs{})
	if err != nil {
		return walkFnErr
	}
	for _, fileInfo := range objs {
		filename := path.Join(name, fileInfo.GetName())
		if err := WalkFS(ctx, depth-1, filename, fileInfo, walkFn); err != nil {
			if err == filepath.SkipDir {
				break
			}
			return err
		}
	}
	return nil
}