'Installs and initializes optimizers.
Parameters
kvstore : str or KVStore
Defaults to `\'local\'`.
optimizer : str or Optimizer
Defaults to `\'sgd\'`.
optimizer_params : dict
Defaults to ``((\'learning_rate\', 0.01),)``. The default value is not a dictionary,
just to avoid pylint warning of dangerous default values.
force_init : bool
Defaults to ``False``, indicates whether to force re-initializing an optimizer
if it is already installed.
Examples
>>> # An example of initializing optimizer.
>>> mod.init_optimizer(optimizer=\'sgd\', optimizer_params=((\'learning_rate\', 0.005),))'

def init_optimizer(self, kvstore='local', optimizer='sgd', optimizer_params=(('learning_rate', 0.01),), force_init=False):

    raise NotImplementedError()
