This is xnu-4903.221.2. See this file in:
Directory listing for xnu-4903.221.2//libkdd
KCDBasicTypeDescription.h
KCDBasicTypeDescription.m
KCDEmbeddedBufferDescription.h
KCDEmbeddedBufferDescription.m
KCDStructTypeDescription.h
KCDStructTypeDescription.m
README.md
kcdata.h
kcdata_core.m
kcdtypes.c
kdd.framework/
kdd.frameworkTests/
kdd.h
kdd.m
kdd.xcodeproj/
kdd_main.m
tests/