how does ubuntu installs itself in an LVM need the installer code url

[Tapas Mishra]

I want to read the script which takes care of installation of Ubuntu
from the ISO when I am installing
Ubuntu in an LVM.The part I want to look at is
when the ISO or installer detects an LVM as a block device it creates
2 parts of that LVM and makes
some filesystem that user specifies and also a swap.
How does it do that part of code I want to look what should I be  looking?