@type t() :: %Inttegro.BroadcastRequest{
  email: Inttegro.ChimeEmailMessageInput.t() | nil,
  message_template: Inttegro.BroadcastRequestMessageTemplate.t() | nil,
  purpose: String.t() | nil,
  recipients: [term()],
  request_meta: Inttegro.BroadcastRequestRequestMeta.t() | nil,
  sender: String.t() | nil
}