public boolean isRetriable() {
        return exception() instanceof RetriableException;
    }
Check if the request is retriable. This is a convenience method for checking if
the exception is an instance of {@link RetriableException}.
@return true if it is retriable, false otherwise
@throws IllegalStateException if the future is not complete or completed successfully
clients/src/main/java/org/apache/kafka/clients/consumer/internals/RequestFuture.java