@Override
  public KnownVersion[] getSerializationVersions() {
    return null;
  }
On each member, search query is executed on one or more {@link IndexRepository}s. A
{@link CollectorManager} could be provided to customize the way results from these repositories
is collected and merged.

@return {@link CollectorManager} instance to be used by function
geode-lucene/src/main/java/org/apache/geode/cache/lucene/internal/distributed/LuceneFunctionContext.java