BigCommerce API Retrieves a specific shipment in an order and update

I tried to using bigcommerce API to retrieves a specific shipment in an order.

Here is my code:

$Orders = BigCommerce_Api::getOrder(100);
$order_shipments = Bigcommerce_Api::getCollection('/orders/'.$Orders->id. '/shipments/'. 1, 'Shipment');

but it shows a warning:

array_map(): Argument #2 should be an array in C:\xampp\htdocs\comm\Bigcommerce\Api.php on line 220

Can anyone help me with this?

Already solve this got some coding error in the Big Commerce API

in Resources.php update code

class Bigcommerce_Api_Shipment extends Bigcommerce_Api_Resource {

protected $ignoreOnCreate = array(
    'id',
    'order_id',
    'date_created',
    'customer_id',
    'shipping_method',
);

protected $ignoreOnUpdate = array(
    'id',
    'order_id',
    'date_created',
    'customer_id',
    'shipping_method',
    'items',
    'billing_address',
    'shipping_address',
);

public function create()
{
    return Bigcommerce_Api::createResource('/orders/' . $this->order_id . '/shipments', $this->getCreateFields());
}

public function update()
{
        return Bigcommerce_Api::updateResource('/orders/' . $this->order_id . '/shipments/' . $this->id, $this->getUpdateFields());

}

}