DomainClassConverter now delays the initialization of the Repositories instances used to avoid the premature initialization of repository instances as that can cause deadlocks if the infrastructure backing the repositories is initialized on a separate thread.
Refactored nested converter classes to allow them to be static ones.
Related issues: spring-projects/spring-boot#16230, spring-projects/spring-framework#25131.
Original pull request: #445.
210ab249e3