class_docstr: Flat input list.
code: def __call__(self, nums: List[int]):
      Outputs = NamedTuple("Outputs", [("num", int)])
      return [Outputs(num) for num in nums]
  
file_path: towhee/tests/unittests/mock_operators/flat_operator/flat_operator.py
imports: from typing import NamedTuple, List
  from towhee.operator import Operator, SharedType
label_desc: Use image node_id 2 for calling the FlatOperator obj's underlying member method code with example usage: obj.__call__(nums) and returns: unknown