def test_value_accumulator_can_be_stored_as_bytes():
values = [4.2, -1.3, 10.8]
acc = ValueAccumulator(values)
data = acc.to_bytes()
assert isinstance(data, bytes)
restored_acc = ValueAccumulator.from_bytes(data)
assert acc == restored_acc
def test_value_accumulator_with_one_value_is_stored_as_single_float64():
acc = ValueAccumulator()
acc.add(4.2)
data = acc.to_bytes()
assert struct.unpack('d', data)[0] == 4.2
restored_acc = ValueAccumulator.from_bytes(data)
assert acc == restored_acc