Taken right from the mailing list:
We currently tied the GraphProvider to a specific configuration of a Graph instance. So every time you want a slight permutation on that configuration, you need to create a new GraphProvider instance. I think that we can simplify that and cut down on the proliferation of those instances and in the same moment offer some added flexibility. I was digging through JUnit docs/code and I think there is a way for us to create a "GraphProviderSource" which would annotate a test (rather than @GraphProviderClass). The GraphProviderSource would produce a list of GraphProvider instances to run each test in a suite with. So, if the GraphProviderSource produced 4 different GraphProvider instances, it would execute each test in the suite 4 times (one for each GraphProvider).