public function getPreview($i = null){
        if (!isset($this->previewList)){
            return false;
        }
        if (is_numeric($i)){
            return $this->previewList[$i];
        } else {
            return $this->previewList;
        }
    }
public function getPreview($i = null){
        if (!isset($this->previewList)){
            return false;
        }
        if (is_numeric($i)){
            return $this->previewList[$i];
        } else {
            return $this->previewList;
        }
    }
public function getPreview ( $ i = null ) { if ( ! isset ( $ this -> previewList ) ) { return false ; } if ( is_numeric ( $ i ) ) { return $ this -> previewList [ $ i ] ; } else { return $ this -> previewList ; } }
Returns the specified fulfillment preview, or all of them.

This method will return <b>FALSE</b> if the list has not yet been filled.
The array for a single fulfillment order will have the following fields:
<ul>
<li><b>ShippingSpeedCategory</b> - "Standard", "Expedited", or "Priority"</li>
<li><b>IsFulfillable</b> - "true" or "false"</li>
<li><b>IsCODCapable</b> - "true" or "false"</li>
<li><b>MarketplaceId</b> - marketplace ID</li>
<li><b>EstimatedShippingWeight</b> (optional) - an array with the fields <b>Unit</b> and <b>Value</b></li>
<li><b>FulfillmentPreviewShipments</b> (optional)- array of shipments:</li>
<ul>
<li><b>EarliestShipDate</b> - ISO 8601 date format</li>
<li><b>LatestShipDate</b> - ISO 8601 date format</li>
<li><b>EarliestArrivalDate</b> - ISO 8601 date format</li>
<li><b>LatestArrivalDate</b> - ISO 8601 date format</li>
<li><b>FulfillmentPreviewItems</b> - array of items</li>
<ul>
<li><b>SellerSKU</b> - SKU</li>
<li><b>SellerFulfillmentOrderItemId</b> - unique ID for the item</li>
<li><b>Quantity</b> - quantity in the shipment</li>
<li><b>EstimatedShippingWeight</b> - an array with the fields <b>Unit</b> and <b>Value</b></li>
<li><b>ShippingWeightCalculationMethod</b> - "Package" or "Dimensional"</li>
</ul>
</ul>
<li><b>EstimatedFees</b> (optional)- array of fees</li>
<ul>
<li><b>Name</b> - name of the fee</li>
<li><b>CurrencyCode</b> - currency for the fee</li>
<li><b>Value</b> - value for the fee</li>
</ul>
<li><b>UnfulfillablePreviewItems</b> (optional)- array of items</li>
<ul>
<li><b>SellerSKU</b> - SKU</li>
<li><b>SellerFulfillmentOrderItemId</b> - unique ID for the item</li>
<li><b>Quantity</b> - quantity of the item</li>
<li><b>ItemUnfulfillableReasons</b> - message as to why the item is unfulfillable</li>
</ul>
<li><b>OrderUnfulfillableReasons</b> (optional)- array of message strings</li>
<li><b>ScheduledDeliveryInfo</b> (optional)- time zone and array of delivery windows</li>
<ul>
<li><b>DeliveryTimeZone</b> - IANA time zone name</li>
<li><b>DeliveryWindows</b> - array of delivery windows</li>
<ul>
<li><b>StartDateTime</b> - ISO 8601 date format</li>
<li><b>EndDateTime</b> - ISO 8601 date format</li>
</ul>
</ul>
</ul>
@param int $i [optional] <p>List index to retrieve the value from.
If none is given, the entire list will be returned. Defaults to NULL.</p>
@return array|boolean array, multi-dimensional array, or <b>FALSE</b> if list not filled yet
Returns the specified fulfillment preview or all of them .