Using Guzzle 6 Middleware in a Laravel Application

The most significant change between Guzzle 5 and 6 is moving away from the event system I grew so accustomed to in Version 5 to middleware in version 6. Needless to say, it was a big adjustment for me at first and it felt like a downgrade. After my initial grumbling, the upgrade guide explains the reasoning for the change:

Instead of using the event system to listen for things like the before event, you now create a stack based middleware function that intercepts a request on the way in and...