Web Services :: Code Implementation Generated By Axis2 Code Generator?

I was a bit confused of the code generated by the Axis2 Code Gen.

I have created a logIn(String username, String password) method in my service and used Axis2 Code Gen to generate the Stub.

I try to access the logIn method from my Client using the Stub like below:

TestServiceStub stub = new TestServiceStub("http://localhost:8080/axis2/services/TestService");
String test = stub.logIn("user","pass").

but instead of UserName and password as the parameters, the Stub created a Login object as the parameter for the logIn method. like the one below:

stub.logIn(Login login1);

I wanted to try the logIn method by providing a static userName and password but it seems impossible because the Stub changed the parameter for the logIn method.

how to test the logIn method.