Create DynamoDB classes

- [Lecturer] So now that we've imported those model objects…that we downloaded from the mobile hub,…the next thing that we're going to do…is create a couple of new classes…that will help us communicate with the database.…So I'm here in my AWSProvider class…and I'm going to add a couple of new properties.…First one I'm gonna call dbClient,…and that's gonna be an instance of AmazonDynamoDBClient.…And what that object will do…is handle the network communication…between our project and DynamoDB.…

Then I'm going to add another property,…I'm gonna call that dbMapper,…which is an instance of DynamoDBMapper,…and that object will handle the mapping…between our database and our ListNamesDO…and ListItemsDO objects.…So now I'll write an accessor method…that'll return our AmazonDynamoDBClient,…and initialize it if necessary,…and I'll just call that function getAmazonDynamoDBClient.…

So if our client is null, I'll create one,…and to create the client…we need what's called a credentialsProvider object,…and we can get that from the identity manager.…