public static function updateSignature()
{
$billingAddressSignature = AddressGateway::updateSignature();
array_push($billingAddressSignature, ['options' => ['updateExisting']]);
$signature = array_merge(self::baseSignature(), ['deviceSessionId', 'venmoSdkPaymentMethodCode', 'fraudMerchantId', ['billingAddress' => $billingAddressSignature]]);
return $signature;
}