def __init__(self, filename=None):
        self.filename = None
        if filename:
            self.load(filename)
def test_optional_arguments(self):
        self.assertEqual(self.myfunc('a'), self.expected)
        self.assertEqual(self.myfunc('a', 5), self.expected)
        self.assertEqual(self.myfunc('a', second=5), self.expected)
        self.assertEqual(self.myfunc('a', 5, 5), self.expected)
        self.assertEqual(self.myfunc('a', fourth=[]), self.expected)