Yeah, of course, the immutable list (a.k.a Kotlin'...

# getting-started

[dathoang.se]

Yeah, of course, the immutable list (a.k.a Kotlin's List) only exists at language level, at bytecode level, it's mutable because it's Java's List.
I didn't take a look at the implementation of toList(), but I guess it will do the same thing, maybe?