org.jetbrains.annotations
Annotation Type ReadOnly

@Documented
@Retention(value=CLASS)
@Target(value={METHOD,FIELD,PARAMETER,LOCAL_VARIABLE})
public @interface ReadOnly

Annotate anything of type descendant from Iterable or Iterator with @ReadOnly if the underlying reference is not intended for mutation. Note that such a reference is not guaranteed to be immutable. It may refer to an object mutated elsewhere.