code: private Collection<WriterSegmentProcessor> createWriterProcessors(UpdateableSegmentMetadata segmentMetadata) {
          ImmutableList.Builder<WriterSegmentProcessor> builder = ImmutableList.builder();
          this.extensions.values().forEach(p -> builder.addAll(p.createWriterSegmentProcessors(segmentMetadata)));
          return builder.build();
      }
docs: Creates WriterSegmentProcessors for the given Segment Metadata from all registered Extensions.
  
  @param segmentMetadata The Segment Metadata to create WriterSegmentProcessors for.
  @return A Collection of processors.