Best properly way to destroy a 2 dimensional array?

[Jonathan Villa via Digitalmars-d-learn]

On Wednesday, 6 April 2016 at 19:54:32 UTC, Jonathan Villa wrote:
> I wrote a little program that given some number it generates a

TL;DR: My program generates a very large `ubyte[][]`, and after I 
call destroy and GC.collect() and GC.minimize(), the memory 
occuping doesn't seems to decrease.