$ java --enable-native-access=ALL-UNNAMED -cp build/classes demo.Arenas
== confined: one owner thread
owner reads -> ok
other thread reads -> WrongThreadException: Attempted access outside owning thread
other thread closes -> WrongThreadException: Attempted access outside owning thread
read after close -> IllegalStateException: Already closed
close twice -> IllegalStateException: Already closed
== shared: any thread, one close
other thread reads -> ok
other thread closes -> ok
read after close -> IllegalStateException: Already closed
== auto: the garbage collector frees it; close() is not allowed
allocate 8 bytes -> ok
close() -> UnsupportedOperationException: Attempted to close a non-closeable session
== global: never freed; close() is not allowed
allocate 8 bytes -> ok
close() -> UnsupportedOperationException: Attempted to close a non-closeable session
== bounds: a segment knows its size
read int at offset 0 -> ok
read int at offset 4 -> IndexOutOfBoundsException: Out of bound access on segment MemorySegment{ kind: native, address: 0x7fba74666600, byteSize: 4 }; new offset = 4; new length = 4
read long at offset 0 -> IndexOutOfBoundsException: Out of bound access on segment MemorySegment{ kind: native, address: 0x7fba74666600, byteSize: 4 }; new offset = 0; new length = 8