(self, optim)
abstract method, register an optimizer `optim`, only needed if `add()` is
        called without a value for the `optim` argument
abstract method, register an optimizer `optim`, only needed if `add()` is
        called without a value for the `optim` argument
abstract method register an optimizer optim only needed if add () is called without a value for the optim argument
def register(self, optim):
        """abstract method, register an optimizer `optim`, only needed if `add()` is
        called without a value for the `optim` argument"""
        self.optim = optim
def register ( self , optim ) : self . optim = optim