protected ClickHouseNode changeServer(ClickHouseNode currentServer, ClickHouseNode newServer) {
        if (!serverRef.compareAndSet(currentServer, newServer)) {
            newServer = getServer();
        } else if (serverListener != null) {
            serverListener.accept(currentServer, newServer);
        }
        return newServer;
    }
Loads data from deferred input stream. This will remove custom writer set by
{@link #data(ClickHouseWriter)}.

@param input input stream
@return mutation request
clickhouse-client/src/main/java/com/clickhouse/client/ClickHouseRequest.java