rating.ex

defmodule Pipelinex.Rating do
  @enforce_keys ~w(author comment)a
  defstruct @enforce_keys

  def new(params), do: struct!(__MODULE__, params)

  def encode(%__MODULE__{author: author, comment: comment}) do
    %{
      "author" => author,
      "comment" => comment
    }
  end
end

video.ex

defmodule Pipelinex.Video do
  @enforce_keys ~w(title ratings)a
  defstruct @enforce_keys

  def new(params), do: struct!(__MODULE__, params)

  def encode(%__MODULE__{title: title, ratings: ratings}),
    do: %{"title" => title, "ratings" => ratings}
end