Squashed 'subtree_dir/' changes from b272dbc..a848b42

a848b42 Second commit.

git-subtree-dir: subtree_dir
git-subtree-split: a848b42a0d6994ae2e58c631f54920ee3caa8f77
Merge commit '518a94e85b4a34fd9ed6e3507b1689910956a3b4'