@type t() :: %ExStreamClient.Model.MessageRequest{
  attachments: [ExStreamClient.Model.Attachment.t()] | nil,
  custom: %{optional(String.t()) => any()} | nil,
  html: String.t() | nil,
  id: String.t() | nil,
  mentioned_users: [String.t()] | nil,
  mml: String.t() | nil,
  parent_id: String.t() | nil,
  pin_expires: float() | nil,
  pinned: boolean() | nil,
  pinned_at: String.t() | nil,
  poll_id: String.t() | nil,
  quoted_message_id: String.t() | nil,
  restricted_visibility: [String.t()] | nil,
  show_in_channel: boolean() | nil,
  silent: boolean() | nil,
  text: String.t() | nil,
  type: (:system | :regular | :"''") | nil,
  user: ExStreamClient.Model.UserRequest.t() | nil,
  user_id: String.t() | nil
}