def get_absolute_url(self):
        url = self.file.url

        if url.startswith('http:') or url.startswith('https:'):
            return url

        return build_server_url(url)
Testing the boundary of unions is a hard problem
dataset/ETHPy150Open reviewboard/reviewboard/reviewboard/attachments/models.py/FileAttachment.get_absolute_url--crossover with--dataset/ETHPy150Open sympy/sympy/sympy/sets/tests/test_sets.py/test_union_boundary_of_joining_sets