feat: hashable lengths #107

Job	Run time
Linting	10s
Pytest (3.7)	1m 20s
Installation (3.7)	1m 8s
Pytest (3.8)	1m 41s
Installation (3.8)	1m 28s
Pytest (3.9)	1m 35s
Installation (3.9)	1m 24s
Pytest (3.10)	1m 47s
Installation (3.10)	1m 22s
Pytest (3.11)	1m 38s
Installation (3.11)	1m 28s
Coverage / Update Base Coverage	0s
Coverage / Check Pull Request Coverage	13s
	15m 14s

Provide feedback