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And second question: I heard that `Validated` is going away in favour of `Either`. Are there any tutorials how to perform error-accumulating validations with `Either`?

It will remain the same as with `Validated` :slightly_smiling_face:
It's not happening until 2.x.x (hopefully end of Q1 next year), and we'll provide plenty of tutorials and documentation on how to migrate.

Our goal is to make it almost automatically, and if possible I hope to write some migration scripts.