Add typed collection to BUYCart.

Mobile Buy SDK/Mobile Buy SDK/Models/Persistent/BUYCart.h

@@ -27,10 +27,18 @@
 #import "_BUYCart.h"
 
 @class BUYProductVariant;
+@class BUYLineItem;
 
 @interface BUYCart : _BUYCart {}
 
 /**
+ * Array of BUYCartLineItem objects in the cart
+ *
+ * These are different from BUYLineItem objects. The line item objects do include the BUYProductVariant.
+ */
+- (nonnull NSArray<BUYCartLineItem *> *)lineItemsArray;
+
+/**
  *  Returns true if the cart is acceptable to send to Shopify.
  */
 - (BOOL)isValid;

Mobile Buy SDK/Mobile Buy SDK/Models/Persistent/BUYCart.m

@@ -40,8 +40,13 @@
 	}
 	return self;
 }
-
 #endif
+
+- (nonnull NSArray<BUYCartLineItem *> *)lineItemsArray
+{
+	return self.lineItems.array;
+}
+
 - (BOOL)isValid
 {
 	return [self.lineItems count] > 0;