public DirectoryProvider getDirectoryProviderForAddition(Class entity,
    Serializable id,
    String idInString,
    Document document)
return the DirectoryProvider where the given entity will be indexed

 public DirectoryProvider[] getDirectoryProvidersForAllShards()
Ask for all shards (eg to query or optimize)

 public DirectoryProvider[] getDirectoryProvidersForDeletion(Class entity,
    Serializable id,
    String idInString)
return the DirectoryProvider(s) where the given entity is stored and where the deletion operation needs to be applied
id and idInString can be null. If null, all the directory providers containing entity types should be returned

 public  void initialize(Properties properties,
    DirectoryProvider[] providers)
provides access to sharding properties (under the suffix sharding_strategy)
and provide access to all the DirectoryProviders for a given index