error: called `.collect::<Vec<String>>().join("")` on an iterator
  --> $DIR/unnecessary_join.rs:10:10
   |
LL |           .collect::<Vec<String>>()
   |  __________^
LL | |         .join("");
   | |_________________^ help: try using: `collect::<String>()`
   |
   = note: `-D clippy::unnecessary-join` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::unnecessary_join)]`

error: called `.collect::<Vec<String>>().join("")` on an iterator
  --> $DIR/unnecessary_join.rs:19:10
   |
LL |           .collect::<Vec<_>>()
   |  __________^
LL | |         .join("");
   | |_________________^ help: try using: `collect::<String>()`

error: aborting due to 2 previous errors