code: public final void remove(EntityMetadata metadata, Object entity, Object key)
      {
          if (indexer != null)
          {
              if (indexer.getClass().getName().equals(IndexingConstants.LUCENE_INDEXER))
              {
                  ((com.impetus.kundera.index.lucene.Indexer) indexer).unindex(metadata, key, kunderaMetadata, null);
              }
              else
              {
                  indexer.unIndex(metadata.getEntityClazz(), entity, metadata, (MetamodelImpl) kunderaMetadata
                          .getApplicationMetadata().getMetamodel(metadata.getPersistenceUnit()));
              }
          }
      }
docs: Removes an object from Index.
  
  @param metadata
  the metadata
  @param entity
  the entity
  @param key
  the key