# File lib/kwalify/validator.rb, line 188
    def _validate_unique(value, rule, path, errors, uniq_table)
      assert_error "uniq_table=#{uniq_table.inspect}" unless rule.unique || rule.ident
      if uniq_table.key?(value)
        exist_at = uniq_table[value]
        exist_at = "/#{exist_at.join('/')}" if exist_at.is_a?(Array)
        #* key=:value_notunique  msg="is already used at '%s'."
        errors << validate_error(:value_notunique, rule, path, value, exist_at)
      else
        uniq_table[value] = path.dup
      end
    end