Consider:
```
$ cat Main.java
/**
 * @test
 * @compile Main.java
 * @run main Main
 */
public class Main {

    private boolean test(String s, int i) {
        if (s.subSequence(0, 1) instanceof Runnable r) {
            return true;
        }

        Integer dummy;
        switch (i) {
            case 0:
                String clashing = null;
                return true;
            default:
                return true;
        }
    }

    public static void main(String[] args) {
    }
}
```

This leads to (using JDK 24):
```
$ java Main.java
Exception in thread "main" java.lang.VerifyError: Inconsistent stackmap frames at branch target 49
Exception Details:
  Location:
    Main.test(Ljava/lang/String;I)Z @49: iconst_1
  Reason:
    Type top (current frame, locals[4]) is not assignable to 'java/lang/String' (stack map, locals[4])
  Current Frame:
    bci: @25
    flags: { }
    locals: { 'Main', 'java/lang/String', integer }
    stack: { integer }
  Stackmap Frame:
    bci: @49
    flags: { }
    locals: { 'Main', 'java/lang/String', integer, top, 'java/lang/String' }
    stack: { }
  Bytecode:
    0000000: 2b03 04b6 0007 3a04 1904 c100 0d99 000b
    0000010: 1904 c000 0d4e 04ac 1cab 0000 0000 0018
    0000020: 0000 0001 0000 0000 0000 0013 013a 0404
    0000030: ac04 ac
  Stackmap Table:
    same_frame(@24)
    same_frame(@44)
    append_frame(@49,Top,Object[#8])

        at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
        at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3035)
        at java.base/java.lang.Class.getMethodsRecursive(Class.java:3177)
        at java.base/java.lang.Class.findMethod(Class.java:2465)
        at java.base/java.lang.System$1.findMethod(System.java:1980)
        at java.base/jdk.internal.misc.MethodFinder.findMainMethod(MethodFinder.java:86)
        at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.execute(SourceLauncher.java:194)
        at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.run(SourceLauncher.java:138)
        at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.main(SourceLauncher.java:76)
```