`contains_key`: https://github.com/rust-lang/hashbrown/blob/158fdd577eec997a0a6af13313dd395219fddabb/src/map.rs#L1416-L1426
`get` literally calls `contains_key`.
On the positive side, I learned something.
...
* Single quotes are for characters, double quotes for strings.
| GitHub pages | https://mattei.io |
| https://twitter.com/kristofmattei |