AsyncUpdate tests that the given database can Update existing metadata in an asynchronous scenario.

ListKeys test the given database in listing the keys it has.

New creates a new in-memory metadata DB, using an nothing but an in-memory map as its storage medium.

RoundTrip simply tests test the client's set-get-delete cycle for all kinds of metadata.

SyncUpdate tests that the given database can Update existing metadata in a synchronous scenario.

DB defines client to store metadata, storing the an in-memory metadata database, used to store encoded metadata directly in an in-memory map.