The interface for search implementations.
Searchable is the abstract network protocol for searching. Implementations provide search over a single index, over multiple indices, and over indices on remote servers.
Queries, filters and sort criteria are designed to be compact so that they may be efficiently passed to a remote index, with only the top-scoring hits being returned, rather than every matching hit. NOTE: this interface is kept public for convenience. Since it is not expected to be implemented directly, it may be changed unexpectedly between releases.
@deprecated In 4.0 this interface is removed/absorbedinto IndexSearcher