error[E0502]: cannot borrow `query` as immutable because it is also borrowed as mutable
  --> tests/ui/system_state_iter_mut_overlap_safety.rs:18:13
   |
15 |         let mut_vec = query.iter_mut().collect::<Vec<bevy_ecs::prelude::Mut<A>>>();
   |                       ---------------- mutable borrow occurs here
...
18 |             query.iter().collect::<Vec<&A>>(),
   |             ^^^^^^^^^^^^ immutable borrow occurs here
...
23 |             mut_vec.iter().map(|m| **m).collect::<Vec<A>>(),
   |             -------------- mutable borrow later used here
