class SmokeMonster(object):
    """
   A large smoke monster that protects the island.
   """

def __init__(self, speed):
    """
      :param speed: Velocity in MPH of the smoke monster
      :type  speed: int
      .. document private functions
      .. automethod:: _evaporate
      """
self.speed = speed

def _evaporate(self):
    pass
How can I use Sphinx' Autodoc-extension for private methods?