# File src/ruby_supportlib/phusion_passenger/vendor/union_station_hooks_core/lib/union_station_hooks_core.rb, line 281
    def check_initialized
      return if !should_initialize? || initialized?
      return if !config.fetch(:check_initialized, true)

      if defined?(::Rails)
        message = 'The Union Station hooks are not initialized. Please ensure ' \
          'that you have an initializer file ' \
          '`config/initializers/union_station.rb` in which you call ' \
          "this:\n\n" \
          "  if defined?(UnionStationHooks)\n" \
          "    UnionStationHooks.initialize!\n" \
          "  end"
      else
        message = 'The Union Station hooks are not initialized. Please ensure ' \
          'that the following code is called during application ' \
          "startup:\n\n" \
          "  if defined?(UnionStationHooks)\n" \
          "    UnionStationHooks.initialize!\n" \
          "  end"
      end

      STDERR.puts(" *** WARNING: #{message}")
      @@config[:initialize_from_check] = true
      initialize!
      report_internal_information('HOOKS_NOT_INITIALIZED', message)
    end