amount parameter in takeOrder function

[bugduino]

Hi
I'm trying to take orders (both a buys orders and sells orders), following the taker.js example
the problem I have is with the amount parameter.
The example is doing the following things

desiredAmountBase = 0.001;
fraction = Math.min(desiredAmountBase} / order.ethAvailableVolumeBase, 1);
const amount = order.amountGet.times(new BigNumber(String(fraction)));

I have the following questions:

1. should I always use ethAvailableVolumeBase both for buys and sells?

2. fraction would obviously be a floating point and so would be amount, but amount should always be in amountGet terms which is in wei and so don't need to be a floating point, is it correct and safe to do

   amount = amount.toNumber();

to truncate decimals?

3. the amount should be written as something like

   const amount = (order.amountGet - order.amountFilled).times(new BigNumber(String(fraction)));

because otherwise you could potentially trying to get more quantity than the available one, is this reasoning correct?