def pruneDutycycles(self, threshold=0.0):
    """
    Prune all the units with dutycycles whose absolute magnitude is less than
    the given threshold
    :param threshold: min threshold to prune. If less than zero then no pruning
    :type threshold: float
    """
    if threshold < 0.0:
      return

    # Collect all layers with 'dutyCycle'
    for m in self.modules():
      if m == self:
        continue
      if hasattr(m, 'pruneDutycycles'):
        m.pruneDutycycles(threshold)
Prune all the units with dutycycles whose absolute magnitude is less than
    the given threshold
    :param threshold: min threshold to prune. If less than zero then no pruning
    :type threshold: float