[Haskell-cafe] Hedgehog - Integrated shrinking, shrinks obey invariants by construction.

Hi everyone, I found the above interesting sentence in Hedgehog's [1] documentation. What does this mean? Is construction there somewhat tied to shrinking, perhaps something like going in the reverse direction? Thanks, Petr [1] https://github.com/hedgehogqa/haskell-hedgehog#features