   above. If you do this, do it in an isolated connection (open a new one if necessary)
   to avoid mixing things up.
   """
+  # TODO: use @doc since directly when we depend on 1.7+.
   if Version.match?(System.version(), "~> 1.7"), do: @doc(since: "0.8.0")
 
   @spec transaction_pipeline(connection(), [command()], keyword()) ::

      ["OK", "foo"]

  """
  if Version.match?(System.version(), "~> 1.7"), do: @doc(since: "0.8.0")

  @spec transaction_pipeline!(connection(), [command()], keyword()) :: [

      {:ok, "1"}

  """
  # TODO: use @doc since directly when we depend on 1.7+.
  if Version.match?(System.version(), "~> 1.7"), do: @doc(since: "0.8.0")

  @spec noreply_command(connection(), command(), keyword()) ::
