A better example for Java would be something like lambda expressions on functional interfaces. There, the compiler is creating an anonymous object that implements the interface. A reversable decompiler will just see the anonymous class instance whereas an analytical decompiler can detect that it is likely a lambda expression due to it being an anonymous class object implementing a single method interface and is being passed to a function argument that takes that interface as a parameter.

In C# yield is implemented as a state machine, so an analytical decompiler could recognise that construct.

And yes, for JVM decompilers it could have language heuristics to detect (or be specifically for) Lombok, Scala, Groovy, Kotlin, etc.

[1] https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaex...

> When you compile your project with IntelliJ IDEA build tool, the IDE adds assertions to all code elements annotated with @NotNull. These assertions will throw an error if the elements happen to be null at runtime.