Updated documentation for serialize

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@513 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/test/base_test.rb

@@ -609,8 +609,6 @@ def test_serialized_attribute
     topic = Topic.create("content" => myobj)  
     Topic.serialize("content", MyObject)
     assert_equal(myobj, topic.content)
-
-    assert_equal(myobj, topic.content)
   end
 
   def test_serialized_attribute_with_class_constraint