message: Import from std rather than core
  Summary: We had two instances of using from core. One goes away in Let's kill the other.
diff: @@ -67,7 +67,7 @@ pub(crate) fn indented<'a, D: ?Sized>(f: &'a mut D, indentation: &'static str) -
  #[cfg(test)]
  mod tests {
  - use core::fmt::Write as _;
  + use std::fmt::Write as _;
  use super::*;
  