    def test_big_arrays(self):
        L = (1 << 31) + 100000
        tmp = mktemp(suffix='.npz')
        a = np.empty(L, dtype=np.uint8)
        np.savez(tmp, a=a)
        del a
        npfile = np.load(tmp)
        a = npfile['a']
        npfile.close()
        os.remove(tmp)