warning: this call to `clone` can be replaced with `std::slice::from_ref`
  --> src/highlight/file_tester.rs:91:13
   |
91 |             &[self.working_directory.clone()],
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::slice::from_ref(&self.working_directory)`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#cloned_ref_to_slice_refs
   = note: requested on the command line with `-W clippy::cloned-ref-to-slice-refs`