my $spec = {
    'Parameters' => [
        'shipmentIncrementId' => {
            'required' => 1,
            'type' => 'string',
        },  
        'carrier' => {
            'required' => 1,
            'type' => 'ups|usps|dhl|fedex|dhlint|custom',
        },  
        'title' => {
            'required' => 1,
            'type' => 'string',
        },  
        'trackNumber' => {
            'required' => 1,
            'type' => 'string',
        },  
    ],  
    'Response' => 'scalar',
};