Definir un tipo array para Server NuSoap

gistfile1.php

<?php 
// ... Server NuSoap

$server->wsdl->addComplexType(
    'Product',
    'complexType',
    'struct',
    'all',
    '',
    array(
        'Name' => array('name'=>'name','type'=>'xsd:string'),
        'Code' => array('name'=>'product_number','type'=>'xsd:string'),
	'Price' => array('name'=>'price','type'=>'xsd:decimal'),
        'Ammount' => array('name'=>'quantity','type'=>'xsd:int')
    )
);

$server->wsdl->addComplexType(
    'ProductArray',
    'complexType',
    'array',
    '',
    'SOAP-ENC:Array',
    array(),
    array(
        array('ref'=>'SOAP-ENC:arrayType','wsdl:arrayType'=>'tns:Product[]')
    ),
    'tns:Product'
);

$server->register(
   'GetProductsByCode',
   array('user'=>'xsd:string','password'=>'xsd:string','product_code'=>'xsd:string'),
   array('return'=>'tns:ProductArray'),
   $NAMESPACE);

//http://share.ez.no/forums/developer/nusoap-registering-complex-data-types