private boolean awaitNodeReady(Node node, FindCoordinatorRequest.CoordinatorType coordinatorType) throws IOException {
        if (NetworkClientUtils.awaitReady(client, node, time, requestTimeoutMs)) {
            if (coordinatorType == FindCoordinatorRequest.CoordinatorType.TRANSACTION) {
                // Indicate to the transaction manager that the coordinator is ready, allowing it to check ApiVersions
                // This allows us to bump transactional epochs even if the coordinator is temporarily unavailable at
                // the time when the abortable error is handled
                transactionManager.handleCoordinatorReady();
            }
            return true;
        }
        return false;
    }
Closes the sender without sending out any pending messages.
clients/src/main/java/org/apache/kafka/clients/producer/internals/Sender.java