def inject(clients={})
      @_injected_clients = true
      clients.each_pair do |name, client|
        _close_if_present(@_connections[name])
        @_connections[name] = Redis::Namespace.new(DEFAULT_NAMESPACE, redis: client)
      end
    end
def inject(clients={})
      @_injected_clients = true
      clients.each_pair do |name, client|
        _close_if_present(@_connections[name])
        @_connections[name] = Redis::Namespace.new(DEFAULT_NAMESPACE, redis: client)
      end
    end
Allow to inject pre-built Redis clients

 Before storing a new connection, ensures that any previously
 set client is properly closed.