Ceos format reading

hello I am using snap for reading alos2 sar imagery. This image is on ceos format, I’d like to understant how to decode this format as I’d like to access the raw pixels on the image.
I am having a view to the source code of the snap-engine, which part of this snap-engine deals with ceos alos2 palsar format? I am working with lvl 1.1
Thanks for your help

The CEOS reader for ALOS2 is in s1tbx-io