code: def get_memory_usage(self):
      return functools.reduce(operator.mul, self.shape) * 4
  
imports: from caffe2.python.optimizer import FP16_ENGINES, Optimizer
  from caffe2.python.helpers.arg_scope import get_current_scope
  from caffe2.python import schema
  from caffe2.python.layers.layers import get_categorical_limit, get_key, IdList, IdScoreList, IdListWithEvicted, IdScoreListWithEvicted, LayerPsParam, ModelLayer, almost_equal_schemas
  import collections
  import functools
  import logging
  import math
  import numpy
  import operator
label_desc: Use image node_id 2 for calling the SparseLookup obj's underlying member method code with example usage: obj.get_memory_usage() and returns: unknown