如何在CodeIgniter中创建库类的多个实例？

// application/libraries/My_library.php
class My_library {
    public function some_method() {
        // ...
    }
}

// application/controllers/My_controller.php
class My_controller extends CI_Controller {
    public function index() {
        // Load the first instance of the library
        $this->load->library('my_library', NULL, 'my_library_instance_1');
        
        // Load the second instance of the library
        $this->load->library('my_library', NULL, 'my_library_instance_2');
        
        // Call some_method() on the first instance
        $this->my_library_instance_1->some_method();
        
        // Call some_method() on the second instance
        $this->my_library_instance_2->some_method();
    }
}