Removing items from the Keychain

- [Instructor] We can avoid the duplicate item error…upon adding an item to the key chain…by removing it if it already exists.…So, let's add a new method through…the key chain facade class.…I'm going to switch to our key chain facade file.…Let's make some place here…and let's add a new method called remove string.…I'm going to make it public too.…The method has a single argument of type string.…This is the unique identifier of the item…we want to delete from the key chain.…

I mark the method as throw able…since removing an item from the key chain…might fail for various reasons.…Let me scroll up a bit.…Next, we'll validate the key.…I'm going to use the guard statement.…The key shouldn't be empty.…As I print a warning message…and throw a key chain facade error.…The message is key must be valid…and I throw an error of type invalid content.…

If everything goes well and our key is valid…we can use the set item delete function to delete the item.…This function takes a query dictionary…with the attributes of the item to be deleted.…