code: @SuppressWarnings("unchecked")
      public static <A extends DestroyAttempt.KillAttempt & DestroyAttempt.TermAttempt> A terminated() {
          return (A) ALREADY_TERMINATED;
      }
docs: Gets an immutable instance that represents an attempt where the process is already terminated.
  This attempt's {@link DestroyAttempt#result() result()} method will return
  {@link DestroyResult#TERMINATED TERMINATED}.
  @param <A> kill or term attempt type
  @return