Step 5 - Challenge: Implementing Key Expiry
In this step your goal is to extend your support for the SET command so that you also accept the EX, PX EAXT PXAT expiry options. Refer to the SET command documentation for details of each option.
I strongly encourage you to automate the testing of these so you can set the values and get them both before and after the expiry to verify they are both set and expired correctly.
When you’re implementing your expiry think about how you can make it low overhead - Redis itself guarantees that expiry is a constant time operation.