OrderedHash#each returns self not ordered_keys

lib/mongo/util/ordered_hash.rb

@@ -67,6 +67,7 @@ class OrderedHash < Hash
     def each
       @ordered_keys ||= []
       @ordered_keys.each { |k| yield k, self[k] }
+      self
     end
 
     def values

test/test_ordered_hash.rb

@@ -72,6 +72,8 @@ class OrderedHashTest < Test::Unit::TestCase
 
     @oh['z'] = 42
     assert_equal keys, @oh.keys
+
+    assert_equal @oh, @oh.each {|k,v|}
   end
 
   def test_values