def episodes_grouped_by_id
      @episodes_grouped_by_id ||= episodes.inject({}) { |hash, episode|
        hash[episode.id.to_s] = episode
        hash
      }
    end
def episodes_grouped_by_id
      @episodes_grouped_by_id ||= episodes.inject({}) { |hash, episode|
        hash[episode.id.to_s] = episode
        hash
      }
    end
Properties: