in / !in
Also written: in, !in
`in` checks whether a value is in a range or collection, and `!in` checks that it isn't. For example, `12 in 1..20` is `true`.
Also written: in, !in
`in` checks whether a value is in a range or collection, and `!in` checks that it isn't. For example, `12 in 1..20` is `true`.