def load_graphml(self, uri):
        raise NotImplementedError
When the manifest is sourced from a url, the source should be the url.
dataset/ETHPy150Open espeed/bulbs/bulbs/base/graph.py/Graph.load_graphml--crossover with--dataset/ETHPy150Open toumorokoshi/sprinter/sprinter/core/tests/test_manifest.py/TestManifest.test_source_from_url_certificate