public function getCustomerItemQuantity($code = null, $itemCode = null) {
		$subscription = $this->getCustomerSubscription($code);
		if (!$itemCode && count($subscription['items']) > 1) {
			throw new CheddarGetter_Response_Exception("This customer's subscription contains more than one item so you need to provide the code for the item you wish to get", CheddarGetter_Response_Exception::USAGE_INVALID);
		}
		$plan = $this->getCustomerPlan($code);
		if ($itemCode) {
			$item = $plan['items'][$itemCode];
			$itemQuantity = $subscription['items'][$itemCode];
		} else {
			$item = current($plan['items']);
			$itemQuantity = current($subscription['items']);
		}
		return array(
			'item' => $item,
			'quantity' => $itemQuantity
		);
	}