def METHOD_NAME(self, mock_post):
    mock_post.return_value = response.encode()
    client = Client.from_service(CalculatorSoapAdd)
    params = {"Body": {"Add": {"intA": 3, "intB": 4}}}
    result = client.send(params, headers={"User-Agent": "xsdata"})
    self.assertIsInstance(result, CalculatorSoapAddOutput)
    self.assertEqual(7, result.body.add_response.add_result)
    obj = CalculatorSoapAddInput(body=CalculatorSoapAddInput.Body(add=Add(3, 4)))
    request = client.serializer.render(obj)
    mock_post.assert_called_once_with(
        "http://www.dneonline.com/calculator.asmx",
        data=request,
        headers={
            "User-Agent": "xsdata",
            "content-type": "text/xml",
            "SOAPAction": "http://tempuri.org/Add",
        },
    )