(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code DuplicateStructField)
  (message "duplicate field `x` in struct `Point`")
  (file "<fixture>")
  (span
    (bytes 43 44)
    (range 6 4 6 5)
  )
  (related
    (span
      (file "<fixture>")
      (bytes 33 34)
      (range 5 4 5 5)
      (message "original field declaration")
    )
  )
)