如何在Jenssegers/Laravel/Mongo中将类添加到hasMany关系中

我正试图将hasMany关系从我的Project类添加到我的Version类(项目有许多版本(。

我有这些：

我的项目类-

namespace App;
use Version;
use Jenssegers'Mongodb'Model as Model;
class Project extends Model
{
    protected $fillable = ['title'];
    public function versions()
    {
        return $this->hasMany('Version');
    }
}

我的版本类-

<?php
namespace App;
use Jenssegers'Mongodb'Model as Model;
class Version extends Model
{
    protected $fillable = ['nickname'];
    public function project() 
    {
        return $this->belongsTo('Project');
    }
}

在一条路线上——

public function createVersion(Request $request)
{
    $projectID = $request->input('projectID');
    $version = $request->input('version');
    $project = Project::where('_id', $projectID)->first();
    $version = new Version();
    $version->projectID = $projectID;
    $version->nickname = $version['nickname'];
    $project->versions->save($version);
    return $version;
}

我得到了错误Class 'Version' not found，它指向Model.php。

我是错过了在某个地方添加一个"用途"，还是完全错过了其他东西？