default long getWriteBufferPeriodicFlushTimeoutMs() {
    throw new UnsupportedOperationException(
      "The BufferedMutator::getWriteBufferPeriodicFlushTimeoutMs has not been implemented");
  }
Returns the current periodic flush timeout value in milliseconds.
@return The maximum number of milliseconds how long records may be buffered before they are
        flushed. The value 0 means this is disabled.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/BufferedMutator.java