The following set of switch cases is exhaustive, but javac reports it as not exhaustive:
```
$ cat /tmp/ExhaustivenessError.java
public class ExhaustivenessError {
    private int test(Root r) {
        return switch (r) {
            case Root(R1 _, _, _) -> 0;
            case Root(R2 _, R1 _, _) -> 0;
            case Root(R2 _, R2 _, R1 _) -> 0;
            case Root(R2 _, R2(R1 _, R1 _), R2(R1 _, R1 _)) -> 0;
            case Root(R2 _, R2(R1 _, R1 _), R2(R1 _, R2 _)) -> 0;
            case Root(R2 _, R2(R1 _, R1 _), R2(R2 _, R1 _)) -> 0;
            case Root(R2 _, R2(R1 _, R1 _), R2(R2 _, R2 _)) -> 0;
            case Root(R2 _, R2(R1 _, R2 _), R2(R1 _, R1 _)) -> 0;
            case Root(R2 _, R2(R1 _, R2 _), R2(R1 _, R2 _)) -> 0;
            case Root(R2 _, R2(R1 _, R2 _), R2(R2 _, R1 _)) -> 0;
            case Root(R2 _, R2(R1 _, R2 _), R2(R2 _, R2 _)) -> 0;
            case Root(R2 _, R2(R2 _, R1 _), R2(R1 _, R1 _)) -> 0;
            case Root(R2 _, R2(R2 _, R1 _), R2(R1 _, R2 _)) -> 0;
            case Root(R2 _, R2(R2 _, R1 _), R2(R2 _, R1 _)) -> 0;
            case Root(R2 _, R2(R2 _, R1 _), R2(R2 _, R2 _)) -> 0;
            case Root(R2 _, R2(R2 _, R2 _), R2(R1 _, R1 _)) -> 0;
            case Root(R2 _, R2(R2 _, R2 _), R2(R1 _, R2 _)) -> 0;
            case Root(R2 _, R2(R2 _, R2 _), R2(R2 _, R1 _)) -> 0;
            case Root(R2 _, R2(R2 _, R2 _), R2 _) -> 0;
            //the above is functionally equivalent to:
// case Root(R2 _, R2(R2 _, R2 _), R2(R2 _, R2 _)) -> 0;
        };
    }
    sealed interface Base {}
    record R1() implements Base {}
    record R2(Base b1, Base b2) implements Base {}
    record Root(Base b1, Base b2, Base b3) {}
}
$ javac /tmp/ExhaustivenessError.java
/tmp/ExhaustivenessError.java:3: error: the switch expression does not cover all possible input values
        return switch (r) {
               ^
1 error
```

Note that if the commented-out case is used instead of the last not-commented-out case, javac will consider the switch to be exhaustive, despite these two cases being (on this spot) functionally equivalent.