Squashed 'STI/' changes from 576c8d8..cd21d34

cd21d34 Refactor Decl

git-subtree-dir: STI
git-subtree-split: cd21d343c2a219200d4f55d9303b37b634ecc9af
Merge commit '40dbb998db2914f2f6deaf63d0f3e4a93c80f462' into devt