@type t() ::
  integer()
  | :MODEL_PARAMETER_APPROACH_TYPE_SUPERVISED
  | :MODEL_PARAMETER_APPROACH_TYPE_UNSUPERVISED
  | :MODEL_PARAMETER_APPROACH_TYPE_REINFORCED_LEARNING
  | :MODEL_PARAMETER_APPROACH_TYPE_SEMI_SUPERVISED
  | :MODEL_PARAMETER_APPROACH_TYPE_SELF_SUPERVISED