@type reason() ::
  :traverse
  | :open_file
  | :member
  | :lookup
  | :insert
  | :foldl
  | :delete
  | :delete_all_objects
  | :close

@type t() :: %Spex.Errors.DetsError{
  __exception__: true,
  context: map() | nil,
  reason: reason()
}