@Retention(value=RUNTIME) @Target(value=TYPE) public static @interface HostAccess.Implementable
explicit host access policy is set. The annotation to use for
 this purpose can be customized with HostAccess.Builder.allowImplementationsAnnotatedBy(Class).
 Allowing implementations for all Java interfaces can be enabled with
 HostAccess.Builder.allowAllImplementations(boolean).Context.Builder.allowHostAccess(HostAccess), 
Value.as(Class), 
HostAccess.EXPLICIT