'Args:
multipliers (tuple or list): tuple of (regex, float), or list of tuples.
verbose (bool): whether to print logs or not
log: deprecated
Example:
Use double learning rate for all the bias (as in caffe):
.. code-block:: python
ScaleGradient((\'.*/b\', 2))'

def __init__(self, multipliers, verbose=True, log=None):

    if (not isinstance(multipliers, list)):
        multipliers = [multipliers]
    self.multipliers = multipliers
    if (log is not None):
        logger.warn("'log'    in    ScaleGradient(..)    is    renamed    to    'verbose'.")
        verbose = log
    assert (verbose in [True, False]), verbose
    self._verbose = verbose
    super(ScaleGradient, self).__init__(self._mapper)
