@Override
  public Collection<Document> toDocuments(LuceneIndex index, Object value) {

    if (value == null) {
      return Collections.emptyList();
    }

    LuceneSerializer mapper = getFieldMapper(value, index.getFieldNames());

    Collection<Document> docs = mapper.toDocuments(index, value);
    if (logger.isDebugEnabled()) {
      logger.debug("HeterogeneousLuceneSerializer.toDocuments:" + docs);
    }

    return docs;
  }
Mappers for each individual class type that this class has seen.

Weak so that entry will be removed if a class is garbage collected.
geode-lucene/src/main/java/org/apache/geode/cache/lucene/internal/repository/serializer/HeterogeneousLuceneSerializer.java