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: tag_tree.go
    path of file: ./repos/mayfly-go/server/internal/tag/api/vo
    
    the code of the file until where you have to start completion: package vo

import (
	"mayfly-go/internal/tag/domain/entity"
)

type TagTreeVOS []*entity.TagTree

type TagTreeItem struct {
	*entity.TagTre
    
func (m *TagTreeVOS) ToTrees(pid uint64) []TagTreeItem {
	var resourceTree []TagTreeItem

	list := m.findChildren(pid)
	if len(list) == 0 {
		return resourceTree
	}

	for _, v := range list {
		Children := m.ToTrees(v.Id)
		resourceTree = append(resourceTree, TagTreeItem{v, Children})
	}

	return resourceTree
}