USPS-REST - Void Shipment

{
  "carrier": "USPS-REST",
  "action": "voidshipment",
  "params": {
    "key": "your-key-from-authenticate-request",
    "payment_token": "your-payment-token from PurchasePostage call",
    "shipment_id": "1234567890",
    "test": true
  }
}

<?php
$rs = new RocketShipIt;
$response = $rs->request(
array (
  'carrier' => 'USPS-REST',
  'action' => 'voidshipment',
  'params' => 
  array (
    'key' => 'your-key-from-authenticate-request',
    'payment_token' => 'your-payment-token from PurchasePostage call',
    'shipment_id' => '1234567890',
    'test' => true,
  ),
)
);

rs.request(
  {'action': 'voidshipment',
 'carrier': 'USPS-REST',
 'params': {'key': 'your-key-from-authenticate-request',
            'payment_token': 'your-payment-token from PurchasePostage call',
            'shipment_id': '1234567890',
            'test': True}}

)

rs.request(
  {"carrier"=>"USPS-REST",
 "action"=>"voidshipment",
 "params"=>
  {"key"=>"your-key-from-authenticate-request",
   "payment_token"=>"your-payment-token from PurchasePostage call",
   "shipment_id"=>"1234567890",
   "test"=>true}}

)

rocketshipit.request(
  {
  "carrier": "USPS-REST",
  "action": "voidshipment",
  "params": {
    "key": "your-key-from-authenticate-request",
    "payment_token": "your-payment-token from PurchasePostage call",
    "shipment_id": "1234567890",
    "test": true
  }
}
)