public boolean filter(final long timestamp, final T value) {
    try {
      return tryFilter(timestamp, value);
    } catch (final Exception e) {
      init(timestamp, value);
      return true;
    }
  }
The last stored time and value we compare current point against lastReadTimestamp and
lastReadValue
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/processor/downsampling/sdt/SwingingDoorTrendingFilter.java