def __init__(self, version_number: int=DEFAULT_VERSION):
    """Create a hand transitions predictor.

    :param version_number: (int) Version of the predictor system ranging (0-3).

    """
    super(WhereVowelPositionsPredictor, self).__init__()
    self._models[0] = BaseWherePositionPredictor
    self._models[1] = WherePositionPredictorCustoms
    self._models[2] = WherePositionPredictorObserved
    self._models[3] = WherePositionPredictorUnified
    self.set_version_number(version_number)

def get_sights_dim(self):
    """Return the number of sights this predictor was trained for."""
    return self._model.get_sights_dim()

def set_sights_and_predict_coords(self, sights: sppasSights=None, vowels: tuple=None):
    """Set the sights of a face and predict all vowel positions.

        If no sights are provided, it uses default sights. It validates the
        input type and the number of sights before setting them and predicting
        vowel coordinates.

        :param sights: (sppasSights | None)
        :param vowels: (tuple | None) List of vowel position names. Default is all known ones.
        :raises: sppasTypeError: given parameter is not a sppasSights type.
        :raises: NotImplementedError: not the expected number of sights

        """
    if self._model is None:
        raise sppasCuedPredictorError
    self._model.set_sights_and_predict_coords(sights, vowels)

def predict_vowels_coords(self, vowels=('n',)) -> None:
    """Estimate the absolute position of all the vowels.

        Estimate the absolute positions of specified vowels relative to the
        sights of a face. It uses predefined coordinates and calculations
        to determine these positions and stores them in a dictionary.
        Sights must be set before using this method.

        :param vowels: (tuple) List of vowel position names. If unknown, 'n' is used instead.
        :raises: sppasKeyError: Invalid given vowel code.

        """
    self._model.predict_vowels_coords(vowels)

def get_vowel_coords(self, vowel: str='n') -> tuple:
    """Return the absolute position of the given vowel.

        Estimated relatively to the sights of a face. Sights must be set
        before using this method.

        :param vowel: (char) Vowel position name. If unknown, 'n' is used instead.
        :return: tuple(x, y, r) with point coordinates and radius
        :raises: sppasKeyError: Invalid given vowel code.

        """
    return self._model.get_vowel_coords(vowel)