formated_errors=@errors.to_enum# ActiveModel::Errors.to_a is an alias to full_messages, we don't want that
.to_a# but enum.to_a gives back an array
.uniq{|error|[error.inner_error.base]}# dedup cumulated errors from dossier.champs, dossier.champs_public, dossier.champs_private which run the validator one time per association