def test_get_mass(self): chunk = Chunk() self.assertEquals(chunk.get_mass(), 0.0, "bad initial mass") shard1 = Disc(gold, 5) shard2 = Block(gold, self.unitsquare) chunk.shards = [shard1, shard2] self.assertEquals(chunk.get_mass(), (25 * pi + 1) * gold.density, "bad mass")