Extended test_datasets.py to check that self loops and backward edges are added correctly.
The data in test/test_datasets was not consistent with the test, since it implied there are 4 edge types (i.e. adjacency lists have shape [[], [], [], []]). The test was passing anyway, because the fourth list in the data from test/test_datasets is always empty, and the data loading code is written in a way that ignores this discrepancy. The fact that the number of edge types is implied by several things and they can imply different values is a deeper problem, but for now I changed the values in the test to reflect the state of test/test_datasets files.
test_datasets.pyto check that self loops and backward edges are added correctly.test/test_datasetswas not consistent with the test, since it implied there are 4 edge types (i.e. adjacency lists have shape[[], [], [], []]). The test was passing anyway, because the fourth list in the data fromtest/test_datasetsis always empty, and the data loading code is written in a way that ignores this discrepancy. The fact that the number of edge types is implied by several things and they can imply different values is a deeper problem, but for now I changed the values in the test to reflect the state oftest/test_datasetsfiles.