code: def unpack_from_dynamodb(*, attrs, expected, model=None, obj=None, engine=None, context=None, **kwargs):
      
      context = context or {"engine": engine}
      engine = engine or context.get("engine", None)
      if not engine:
          raise ValueError("You must provide engine or a context with an engine.")
      if model is None and obj is None:
          raise ValueError("You must provide a model or obj to unpack.")
      if model is not None and obj is not None:
          raise ValueError("Only specify model or obj.")
      if model:
          obj = model.Meta.init()
  
      for column in expected:
          value = attrs.get(column.dynamo_name, None)
          value = engine._load(column.typedef, value, context=context, **kwargs)
          setattr(obj, column.name, value)
      return obj
docs: Push values by dynamo_name into an object