@type t() :: %LINE.Bot.MessagingApi.Model.NarrowcastProgressResponse{
  acceptedTime: DateTime.t(),
  completedTime: DateTime.t() | nil,
  errorCode: integer() | nil,
  failedDescription: String.t() | nil,
  failureCount: integer() | nil,
  phase: String.t(),
  successCount: integer() | nil,
  targetCount: integer() | nil
}