class_docstr: A plain implementation of SGD
  
  :param learningrate learning rate
  :param learningrate_decay learning rate decay
  :param weightdecay weight decay
  :param momentum momentum
  :param dampening dampening for momentum
  :param nesterov enables Nesterov momentum
  :param learningrates 1D tensor of individual learning rates
  :param weightdecays 1D tensor of individual weight decays
  >>> sgd = SGD()
  creating: createDefault
  creating: createSGD
code: def get_optimizer(self):
      return self.optimizer
  
imports: from abc import ABC, abstractmethod
  from bigdl.util.common import DOUBLEMAX
  from zoo.orca.learn.optimizers.schedule import Scheduler
label_desc: Use image node_id 2 for calling the SGD obj's underlying member method code with example usage: obj.get_optimizer() and returns: self