 
   @doc """
   List of keys which we ensure are unchanged from compile time to runtime. For
-  example, the :force_ssl option must be available at compile time in order to 
+  example, the :force_ssl option must be available at compile time in order to
   work properly. We check these keys so we can warn the user that changing the
   option at runtime may lead to undesirable behavior.
   """

    host   = host_to_binary(url[:host] || "localhost")
    port   = port_to_integer(url[:port] || port)

    if host =~ ":" do
      Logger.warn("url: [host: ...] configuration value #{inspect(host)} for #{inspect(endpoint)} is invalid")
    end



  defp cache_static_manifest(endpoint) do
    if inner = endpoint.config(:cache_static_manifest) do
      {app, inner} =
        case inner do
          {_, _} = inner -> inner
          inner when is_binary(inner) -> {endpoint.config(:otp_app), inner}
