public boolean isThreadAlive() {
        return isAlive();
    }
Get the next batch of records by polling.

@param pollTime how long to block in Consumer#poll
@return Next batch of records or null if no records available.
@throws TaskMigratedException if the task producer got fenced (EOS only)
streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamThread.java