completed equals and hashCode

src/main/java/org/zipcoder/store/Cart.java

     public long getId(){
         return this.id;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof Cart)) return false;
+        Cart cart = (Cart) o;
+        return getId() == cart.getId();
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(getId());
+    }
 }

src/main/java/org/zipcoder/store/User.java

     public void setName(String name) {
         this.name = name;
     }
+
+    public boolean equals(User user){
+        if(this.id == user.getId() && this.name == user.getName()) {return true;}
+        return false;
+    }
+    public int hashCode(){
+        return Objects.hash(this.getId(), this.getName());
+    }
 }