(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code CannotAssignImmutableLocal)
  (message "cannot assign to immutable local `x`")
  (file "<fixture>")
  (span
    (bytes 58 59)
    (range 6 8 6 9)
  )
  (hint "declare it with `var` to make it mutable")
)