Support revisions with str type for try jobs.

tests/model_test.py

Index: tests/model_test.py
===================================================================
--- tests/model_test.py	(revision 226737)
+++ tests/model_test.py	(working copy)
@@ -71,7 +71,7 @@
   l = (Basic, dict)
 
 
-class StrDisallowed(PersistentMixIn):
+class StrAllowed(PersistentMixIn):
   m = str
 
 
@@ -228,8 +228,13 @@
     }
     self.assertEqual(expected, data.as_dict())
 
-  def testStrDisallowed(self):
-    self.assertRaises(TypeError, StrDisallowed)
+  def testStrAllowed(self):
+    data = StrAllowed(m='foo')
+    expected = {
+        'm': 'foo',
+        TYPE_FLAG: 'StrAllowed',
+    }
+    self.assertEqual(expected, data.as_dict())
 
 
 class Deserialize(Base):
@@ -377,11 +382,13 @@
     actual = PersistentMixIn.from_dict(marshall(data))
     self._check(actual, TypeOrDict, l={'foo': 'bar'})
 
-  def testStrDisallowed(self):
+  def testStrAllowed(self):
     data  = {
-      TYPE_FLAG: 'StrDisallowed',
+      'm': 'bar',
+      TYPE_FLAG: 'StrAllowed',
     }
-    self.assertRaises(TypeError, PersistentMixIn.from_dict, marshall(data))
+    actual = PersistentMixIn.from_dict(marshall(StrAllowed(m='bar')))
+    self._check(actual, StrAllowed, m='bar')
 
 
 class Mutable(object):