import liquidjava.specification.Refinement;

class Conn {
    public Conn(@Refinement("_ > 0") int port) {}
}

public class Repro {
    static Conn open(String scheme) {
        return switch (scheme) {
            case "tcp" -> {
                yield new Conn(80);
            }
            default -> new Conn(1);
        };
    }
}

Exception in thread "main" java.lang.RuntimeException: 
Error while checking CtMethodImpl
  on open(String scheme) { 
  with 
Error while checking CtBlockImpl
  on { 
  with 
Error while checking CtReturnImpl
  on return switch (scheme) { 
  with 
Error while checking CtSwitchExpressionImpl
  on switch (scheme) { 
  with 
Error while checking CtCaseImpl