Although PHP doesn’t support delegates (as in C#) the possibility to define the __invoke magic method allows us to write code as if we were using delegates in C#. The following video clip shows that.

Stable Values in Java (JEP 502): Deferred Immutability with JVM Trust
Explore Stable Values – a new Java 25 upcoming feature (JEP 502) enabling lazy initialization with immutable performance and JVM-level optimizations.