Finally a good point! I was waiting for someone to bring this up....too bad most of the thread has now denigrated to trolling, name calling and chest thumping.
Yes I am familiar with all sorts of cold testing methodologies. The US continues to do them for example (mostly to gauge effects of worst case warhead aging).
However they carry significant limitations for say moving from gen 1 to gen 2 pit geometries among other issues.
They can test basic conceptual effects of changes to proven designs and give suggested starting points for some further iteration, but they are not a substitute for real tests unless you have a massive test history and access to various critical coefficients and curves that I would assume only US and Russia would have (that can then be used to computer simulate to some higher degree of reliability).
You can read up for example on the Swan and Robin primary testing and how they formed the bedrock for data collection that can be used in advanced cold testing methods, simluation and scaling.
The US for example produces documents such at this one:
http://fas.org/programs/ssp/nukes/nuclearweapons/SSMP-FY2012.pdf
But for Pakistan we have to rely on hearsay and rumor at best....coupled with a Nuclear science and RnD manpower+budget several magnitudes lower than other nuclear powers.
So unless there is some concession from the die-hard "Pakistan tactical nukes are as advanced (or even more advanced) as P5 countries" that there has been significant help from the Chinese on key critical aspects of miniaturisation, reliability assurance (without testing) and quite possibly direct transfer of critical equipment.....I am not buying all this hot air about the Nasr tactical warhead.
If you have some useful information to shed some light on advanced Pakistan cold testing (outside of Kirana which was quite basic), by all means share it.