(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code ArityMismatch)
  (message "function `std.vec.i32.append` called with wrong number of arguments")
  (file "<fixture>")
  (span
    (bytes 43 83)
    (range 5 3 5 43)
  )
  (expected "2")
  (found "1")
)