code: def test_single_value_returned(self):
      payload = """
              {
                  "data": { "_arg1": 2, "_arg2": 40 },
                  "script":
                  "return _arg1 + _arg2"
              }
              """
      headers = {
          "Content-Type": "application/json",
      }
  
      conn = self._get_connection()
      conn.request("POST", "/evaluate", payload, headers)
      response = conn.getresponse()
      result = response.read().decode("utf-8")
  
      self.assertEqual(200, response.status)
      self.assertEqual("42", result)
  
file_path: TabPy/tests/integration/test_evaluate.py
imports: from .None import integ_test_base
  import json
label_desc: Use image node_id 1 for calling the TestEvaluate obj's underlying member method code with example usage: obj.test_single_value_returned() without return types