static PyObject*
_PyErr_CreateException(PyObject *exception_type, PyObject *value)
{
    PyObject *exc;

    if (value == NULL || value == Py_None) {
        exc = _PyObject_CallNoArgs(exception_type);
    }
    else if (PyTuple_Check(value)) {
        exc = PyObject_Call(exception_type, value, NULL);
    }
    else {
        exc = PyObject_CallOneArg(exception_type, value);
    }

    if (exc != NULL && !PyExceptionInstance_Check(exc)) {
        PyErr_Format(PyExc_TypeError,
                     "calling %R should have returned an instance of "
                     "BaseException, not %s",
                     exception_type, Py_TYPE(exc)->tp_name);
        Py_CLEAR(exc);
    }

    return exc;
}