(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code ArityMismatch)
  (message "function `add` called with wrong number of arguments")
  (file "<fixture>")
  (span
    (bytes 82 89)
    (range 8 3 8 10)
  )
  (expected "2")
  (found "1")
)