The System.Callable Interface
You should be aware of the system.callable interface that allows for calling an dynamically specified Apex class without requiring a dependency on a common global interface.
Find more details at https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_interface_System_Callable.htm
This doesn’t invalidate any of the content in the book, but is something that will certainly be included in a future edition.
