@type t() :: %Docspring.Model.UpdateSignatureRequestRequest{
  auth_phone_number_hash: String.t() | nil,
  auth_provider: String.t() | nil,
  auth_second_factor_type:
    Docspring.Model.SignatureRequestAuthSecondFactorType.t() | nil,
  auth_session_id_hash: String.t() | nil,
  auth_session_started_at: DateTime.t() | nil,
  auth_type: Docspring.Model.SignatureRequestAuthType.t() | nil,
  auth_user_id_hash: String.t() | nil,
  auth_username_hash: String.t() | nil,
  metadata: %{optional(String.t()) => any()} | nil
}