def test_load_empty_stack():
state = State(heap={5: 80})
with pytest.raises(exc.StackError):
state.load()
def test_load_key_not_in_heap():
state = State(stack=[5])
with pytest.raises(exc.HeapError):
state.load()
def test_load():
state = State(heap={5: 80}, stack=[5])
state.load()
assert state.stack == [80]