@type t() :: %Envoy.Extensions.Router.ClusterSpecifiers.Lua.V3.LuaConfig{
  __unknown_fields__: [
    {field_number :: integer(), Protobuf.Wire.Types.wire_type(),
     value :: term()}
  ],
  default_cluster: String.t(),
  source_code: Envoy.Config.Core.V3.DataSource.t() | nil
}