$ cargo -q run --example demo --features="detect-color-support"
thread 'main' panicked at examples/demo.rs:36:12:
byte index 1 is not a char boundary; it is inside 'á' (bytes 0..2) of `áöù`
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fn split(value: "áöù", at: 1)
    at examples/demo.rs:35:16
fn rotate_left(value: "áöù", mid: 1)
    at examples/demo.rs:29:16
fn collect_rotations(value: "áöù")
    at examples/demo.rs:22:16
fn app_logic(value.clone(): Wrapper("abc\nbcd"), arr: [1, 2], ..., flag: false)
    at examples/demo.rs:14:16