code: func ShallowSizeOf(obj interface{}) int64 {
  	if obj == nil {
  		return 0
  	}
  	clz := reflect.TypeOf(obj)
  	if clz.Kind() == reflect.Slice {
  		return shallowSizeOfArray(obj)
  	}
  	return ShallowSizeOfInstance(clz)
  }
docs: /*
  Estimates a "shallow" memory usage of the given object. For slices,
  this will be the memory taken by slice storage (no subreferences will
  be followed). For objects, this will be the memory taken by the fields.
  */