Programming Phoenix LiveView: The code provided at Programming Phoenix LiveView: Interactive Elixir Web Programming Without Writing Any JavaScript by Bruce A. Tate and Sophie DeBenedetto is not synced with the book. Specifically, the following code is missing in /distributed_dashboard/pento/lib/pento_web/live/admin/survey_results_live.ex

  def assign_age_group_filter(%{assigns: %{age_group_filter: age_group_filter}} = socket) do
    assign(socket, :age_group_filter, age_group_filter)
  end

  def assign_gender_filter(%{assigns: %{gender_filter: gender_filter}} = socket) do
    assign(socket, :gender_filter, gender_filter)
  end