@type t() :: %ApolloSignal.Types.ActivityResponse{
  id: String.t(),
  metadata: ApolloSignal.Types.ActivityMetadataResponse.t() | nil,
  object: String.t() | nil,
  occurred_at: String.t(),
  reference_id: String.t() | nil,
  reference_name: String.t() | nil,
  type: String.t()
}