def test_non_bijective(self):
        x = Bidict()
        x[1] = 2
        x[3] = 2
        del x[1]
        del x[3]
Tests resilience (not correctness!) under non-bijectiveness.
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/core/data_structures/bijectivedict.py/TestBidict.test_non_bijective