## Implemented extensions
There is a list of implemented extensions and what they include:
-- `rrtext7.cc`: [K-d tree][] for node storage.
+- `rrtext8.cc`: 3D [K-d tree][] for node storage.
+- `rrtext7.cc`: 2D [K-d tree][] for node storage.
- `rrtext6.cc`: Reeds and Shepp for both -- building and search costs,
- `rrtext5.cc`: different cost for building (Reeds and Shepp) and searching
(Euclidean distance),