@type t() :: %Ory.Model.RegistrationFlow{
  active: Ory.Model.IdentityCredentialsType.t() | nil,
  expires_at: DateTime.t(),
  id: String.t(),
  issued_at: DateTime.t(),
  oauth2_login_challenge: String.t() | nil,
  oauth2_login_request: Ory.Model.OAuth2LoginRequest.t() | nil,
  request_url: String.t(),
  return_to: String.t() | nil,
  transient_payload: map() | nil,
  type: String.t(),
  ui: Ory.Model.UiContainer.t()
}