Where is the file proto.c

[Lan Bin]

>From Wessels' Squid v1.2 Prorammer 
Guide, we know there is file proto.c
at Server Side(section 1.2). However
I cant find it in squid 2.1Patch2.
Could anyone give me some information abt 
it? What is the latest file name?

Thanx!

David