def test_two_gate_loop(self):
a = Nand()
b = Nand()
a.o[0].connect(b.i[0])
is_loop = creates_loop(b.o[0],a.i[0])
self.assertTrue(is_loop)
def test_three_gate_non_loop(self):
a = Nand()
b = Nand()
c = Nand()
a.o[0].connect(b.i[0])
is_loop = creates_loop(b.o[0],c.i[0])
self.assertFalse(is_loop)
def test_simple_loop(self):
a = Nand()
is_loop = creates_loop(a.o[0],a.i[0])
self.assertTrue(is_loop)
