Bug Fixes
- Caching ([4](https://github.com/bdraco/index-503/pull/4),
[`a303767`](https://github.com/bdraco/index-503/commit/a3037676d79fb59b0694745161b00a8f74251a39))
- Legacy typing ([5](https://github.com/bdraco/index-503/pull/5),
[`3847fc3`](https://github.com/bdraco/index-503/commit/3847fc342235c81cb9b94c90c366b63215ab7c0f))