Renamed to PowerSign

    return tf.train.GradientDescentOptimizer(learning_rate=learning_rate)

class PowerSignOptimizer(Optimizer):

  """The new powersign optimization algorithm"""

class PowerSign(Optimizer):

  """The powersign optimization algorithm"""

  def __init__(self, learning_rate=0.1, beta=0.9):

    """construct a powerSign optimizer