PHP Activerecord 多對多自我參照( has_many through[many to many] self referential ) Codeigniter How to solution

User.php

<?php

/**
* Alias 用戶關注的資料表
*/
class TargetUser extends User
{
  static $table_name  = "users";
}

/**
* Alias 用戶粉絲的資料表
*/
class FromUser extends User
{
  static $table_name  = "users";
}

class User extends ActiveRecord\Model
{
  static $has_many = array(
    // 用戶的關注
    array('idols_user_references', 'class_name' => "UserReference", 'foreign_key' => "from_user_id"),
    array('idols', 'class_name' => "TargetUser", 'through' => 'idols_user_references', 'foreign_key' => "from_user_id"),
    // 用戶的粉絲
    array('fans_user_references', 'class_name' => "UserReference", 'foreign_key' => "target_user_id"),
    array('fans', 'class_name' => "FromUser", 'through' => 'fans_user_references', 'foreign_key' => "target_user_id"),
  );
}

User2.php

<?php

  class User extends ActiveRecord\Model
  {
    static $has_many = array(
      // 用戶的關注
      array('idols_user_references', 'class_name' => "UserReference", 'foreign_key' => "from_user_id"),
      array('idols', 'class_name' => "User", 'through' => 'idols_user_references', 'foreign_key' => "from_user_id"),
      // 用戶的粉絲
      array('fans_user_references', 'class_name' => "UserReference", 'foreign_key' => "target_user_id"),
      array('fans', 'class_name' => "User", 'through' => 'fans_user_references', 'foreign_key' => "target_user_id"),
    );
  }

  $user = User::first();
	$user->fans;