class_docstr: Test OperatorAction
code: def test_lambda(self):
      f = lambda x: x + 1
      op_action = OperatorAction.from_lambda(f)
      op_info = {
          "operator": f,
          "type": "lambda",
          "init_args": None,
          "init_kws": None,
          "tag": None,
      }
      self.assertEqual(op_action.serialize(), op_info)
  
imports: import unittest
  from towhee.runtime.operator_manager.operator_action import OperatorAction
label_desc: Use image node_id 2 for calling the TestOperatorAction obj's underlying member method code with example usage: obj.test_lambda() without return types