       nil ->
         Pixie.Backend.queue_for client_id, messages
       pid ->
+        GenServer.cast pid, :ping
         Pixie.Transport.enqueue pid, messages
     end
     :ok

  """
  def ping client_id do
    GenServer.cast via(client_id), :ping
  end

  @doc """

    {:ok, transport} = Pixie.TransportSupervisor.replace_child transport_name, id
    do_set_transport id, transport, transport_name
    {:reply, transport, %{state | transport_name: transport_name}, idle_timeout}
  end

  def handle_call({:set_meta, metadata}, _from, state) do
    {:reply, :ok, %{state | metadata: metadata}}
  end

  def handle_call(:get_meta, _from, %{metadata: metadata}=state) do
    {:reply, metadata, state}
  end

  @doc """
