code: protected void notifyMetadataRemoved(Collection<SegmentMetadata> segments) {
          if (segments.size() > 0) {
              Collection<Long> segmentIds = segments.stream().map(SegmentMetadata::getId).collect(Collectors.toList());
              this.readIndex.cleanup(segmentIds);
              this.attributeIndex.cleanup(segmentIds);
          }
      }
docs: Callback that notifies eligible components that the given Segments' metadatas has been removed from the metadata,
  regardless of the trigger (eviction or deletion).
  
  @param segments A Collection of SegmentMetadatas for those segments which were removed.