//In myMapper class, I have this method
public function loadAllPosts() {
    $postObject = new Post();
    $userObject = new User();

    $select = new Select();

    $select->from(['post' => $postObject->tableName()])
           ->join(['user' => $userObject->tableName()], 'post.user= user.id');

    $stmt = $this->m_sql->prepareStatementForSqlObject($select);
    $result = $stmt->execute();

    if($result instanceof ResultInterface && $result->isQueryResult()){
        $postResultSet = new HydratingResultSet(new ClassMethods(), $postObject);
        $userResultSet = new HydratingResultSet(new ClassMethods(), $userObject);
        return [
            'status' => TRUE,
            'posts' => $postResultSet->initialize($result),
            'users' => $doopinResultSet->initialize($result)
        ];
    }

    return [
        'status' => FALSE
    ];
}

//And I were expecting to have data in my service class like this
public function getPosts() {
    $result = $this->m_loginMapper->loadAllPosts();
    $model = [];

    if($result['status']){
        if(!empty($result['users']) && !empty($result['posts'])){
            $users = $result['users'];
            $usersArray = $users->toArray();

            $posts = $result['posts'];
            $postsArray = $posts->toArray();

            foreach ($postsArray as $key => $post) {
                $post = $postsArray[$key];
                $postWithUser = $post->setUser($usersArray[$key]);
                $model[] = $postWithUser;
            }

        } else
            $result['doops'] = NULL;

    }

    return $model;

}

//I always have this exception
/*This result is a forward only result set, calling rewind() after moving forward is not supported

I tried buffer with rewind. but not working. How can I achieve this or is there another way?

Thanks */