t() :: %MailSlurpAPI.Model.AttachmentEntity{
  attachmentId: String.t(),
  contentLength: integer() | nil,
  contentType: String.t() | nil,
  createdAt: DateTime.t(),
  id: String.t() | nil,
  name: String.t() | nil,
  updatedAt: DateTime.t(),
  userId: String.t()
}