validate_fallbacks

# File activesupport/lib/active_support/i18n_railtie.rb, line 91
    def self.validate_fallbacks(fallbacks)
      case fallbacks
      when ActiveSupport::OrderedOptions
        !fallbacks.empty?
      when TrueClass, Array, Hash
        true
      else
        raise "Unexpected fallback type #{fallbacks.inspect}"
      end
    end