warning: called `unwrap` on `root` after checking its variant with `is_none`
  --> crates/tree_availability/src/world_tree/tree_data.rs:86:24
   |
79 |         if root.is_none() {
   |         ----------------- help: try: `if let Some(..) = root`
...
86 |             let root = root.unwrap();
   |                        ^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_unwrap
   = note: `#[warn(clippy::unnecessary_unwrap)]` on by default