Adds a new strong classifier with the given threshold to the cascade.

    **Parameters:**

    classifier : :py:class:`bob.learn.boosting.BoostedMachine`
      A strong classifier to add

    ``threshold`` : float
      The classification threshold for this cascade step

    ``begin``, ``end`` : int or ``None``
      If specified, only the weak machines with the indices ``range(begin,end)`` will be added.

def add(self, classifier, threshold, begin=None, end=None):
    """Adds a new strong classifier with the given threshold to the cascade.

    **Parameters:**

    classifier : :py:class:`bob.learn.boosting.BoostedMachine`
      A strong classifier to add

    ``threshold`` : float
      The classification threshold for this cascade step

    ``begin``, ``end`` : int or ``None``
      If specified, only the weak machines with the indices ``range(begin,end)`` will be added.
    """
    boosted_machine = bob.learn.boosting.BoostedMachine()
    if begin is None: begin = 0
    if end is None: end = len(classifier.weak_machines)
    for i in range(begin, end):
      boosted_machine.add_weak_machine(classifier.weak_machines[i], classifier.weights[i])
    self.cascade.append(boosted_machine)
    self.thresholds.append(threshold)
    self._indices()