[wix-users] How can I check for available disk space in burn bootstrapper?

[Mayooran Macilamany]

I created this installer using burn bootstrapper and I need to show an
error message on my WPF UI if the available disk space is not enough.
Currently I added hook to the CacheComplete event and show and error
message if its args status is less than zero. It works on certain occasion
but in certain other occasions though there is no disk space, this method
still returns zero. What is the correct way to determine if there is enough
space using burn? Any help would be much appreciated.