# File lib/active_support/vendor/i18n-0.4.1/i18n/exceptions.rb, line 22
    def initialize(locale, key, opts = nil)
      @key, @locale, @options = key, locale, opts || {}
      keys = I18n.normalize_keys(locale, key, options[:scope])
      keys << 'no key' if keys.size < 2
      super "translation missing: #{keys.join(', ')}"
    end