def next_uuid(count = @uuid_batch_count)
      if uuids.nil? || uuids.empty?
        @uuids = connection.get("_uuids?count=#{count}")["uuids"]
      end
      uuids.pop
    end
def next_uuid(count = @uuid_batch_count)
      if uuids.nil? || uuids.empty?
        @uuids = connection.get("_uuids?count=#{count}")["uuids"]
      end
      uuids.pop
    end
Retrive an unused UUID from CouchDB. Server instances manage caching a list of unused UUIDs.