Add test for TimeWithZone#to_i with wrapped DateTime

activesupport/test/core_ext/time_with_zone_test.rb

@@ -284,6 +284,12 @@ class TimeWithZoneTest < Test::Unit::TestCase
     assert_equal 946684800, result
     assert result.is_a?(Integer)
   end
+  
+  def test_to_i_with_wrapped_datetime
+    datetime = DateTime.civil(2000, 1, 1, 0)
+    twz = ActiveSupport::TimeWithZone.new(datetime, @time_zone)
+    assert_equal 946684800, twz.to_i
+  end
 
   def test_to_time
     assert_equal @twz, @twz.to_time