class_docstr: Add operator that can take in undefined amount of inputs and saves results to '<input_name>_sum'
  column of result dataframe.
code: def shared_type(self):
      return SharedType.Shareable
  
imports: from typing import NamedTuple
  from towhee.operator import Operator, SharedType
label_desc: Use image node_id 3 for calling the AddOperatorV2 obj's underlying member method code with example usage: obj.shared_type() and returns: SharedType