onPanic@Jesuisfoudell:~
$ find /etc/apt -type f -name '*.list' -exec bash -c 'echo -e "\n$1"; nl -ba "$1"' _ '{}' \;

/etc/apt/sources.list
     1	#this file is empty by default.  Sources are under /etc/apt/souces.list.d

/etc/apt/sources.list.d/virtualbox.list
     1	deb http://download.virtualbox.org/virtualbox/debian bullseye contrib

/etc/apt/sources.list.d/debian-stable-updates.list
     1	# Debian bullseye Updates
     2	deb http://deb.debian.org/debian bullseye-updates main contrib non-free

/etc/apt/sources.list.d/mx.list
     1	# MX Community Main and Test Repos
     2	deb http://ftp.lip6.fr/pub/linux/distributions/mxlinux/packages/mx/repo/ bullseye main non-free
     3	#deb http://ftp.lip6.fr/pub/linux/distributions/mxlinux/packages/mx/testrepo/ bullseye test
     4	
     5	#ahs hardware stack repo
     6	#deb http://ftp.lip6.fr/pub/linux/distributions/mxlinux/packages/mx/repo/ bullseye ahs

/etc/apt/sources.list.d/debian.list
     1	# Debian Stable.
     2	deb http://deb.debian.org/debian bullseye main contrib non-free
     3	deb http://security.debian.org/debian-security bullseye-security main contrib non-free
     4	#deb-src http://deb.debian.org/debian bullseye main contrib non-free 
     5	
     6	#bullseye backports
     7	#deb http://deb.debian.org/debian bullseye-backports main contrib non-free
DonPanic@Jesuisfoudell:~
$ find /etc/apt -type f -name '*.list' -exec bash -c 'echo -e "\n$1"; nl -ba "$1"' _ '{}' \;

/etc/apt/sources.list
     1	#this file is empty by default.  Sources are under /etc/apt/souces.list.d

/etc/apt/sources.list.d/virtualbox.list
     1	deb http://download.virtualbox.org/virtualbox/debian bullseye contrib

/etc/apt/sources.list.d/debian-stable-updates.list
     1	# Debian bullseye Updates
     2	deb http://deb.debian.org/debian bullseye-updates main contrib non-free

/etc/apt/sources.list.d/mx.list
     1	# MX Community Main and Test Repos
     2	deb http://ftp.lip6.fr/pub/linux/distributions/mxlinux/packages/mx/repo/ bullseye main non-free
     3	#deb http://ftp.lip6.fr/pub/linux/distributions/mxlinux/packages/mx/testrepo/ bullseye test
     4	
     5	#ahs hardware stack repo
     6	#deb http://ftp.lip6.fr/pub/linux/distributions/mxlinux/packages/mx/repo/ bullseye ahs

/etc/apt/sources.list.d/debian.list
     1	# Debian Stable.
     2	deb http://deb.debian.org/debian bullseye main contrib non-free
     3	deb http://security.debian.org/debian-security bullseye-security main contrib non-free
     4	#deb-src http://deb.debian.org/debian bullseye main contrib non-free 
     5	
     6	#bullseye backports
     7	#deb http://deb.debian.org/debian bullseye-backports main contrib non-free