Basically, it is a dynamic bounding volume hierarchy (BVH) using axis-aligned bounding boxes (AABBs). The data structure provides an efficient way of detecting potential overlap between objects of arbitrary shape and size and is commonly used in computer games engines for collision detection and ray tracing.
Since I am a lazy developer, you can find my terrible test files in the source. Also I am working on a simple platformer for testing this library: https://github.com/selimanac/DAABBCC-Platformer. You can test the platformer example on itch.io.