presto-main/src/main/java/io/prestosql/operator/Driver.java/Driver/checkOperatorFinishedRevoking
class Driver:    @GuardedBy("exclusiveLock")
    private void checkOperatorFinishedRevoking(Operator operator)
    {
        ListenableFuture<?> future = revokingOperators.get(operator);
        if (future.isDone()) {
            getFutureValue(future); // propagate exception if there was some
            revokingOperators.remove(operator);
            operator.finishMemoryRevoke();
            operator.getOperatorContext().resetMemoryRevokingRequested();
        }
    }