As PHP improves optional typing, we've been making use of it in this project, since it avoids the need to validate things extensively across the entire API surface.

Strict typing is being introduced here as well, which prevents type coercion, which can act in surprising ways.

declare(strict_types=1);

The following classes do not have this feature enabled, since it turns out w

https://en.wikipedia.org/wiki/Patch_Code