addressed some comments by P.L., some docstrings are still missing

theano/configdefaults.py

@@ -547,9 +547,9 @@ AddConfigVar('check_input',
              BoolParam(True))
 
 AddConfigVar('cache_optimizations',
-             "WARNING: work in progress, does not work yet."
-             "Specify if the optimization cache should be used. This cache will"
-             "any optimized graph and its optimization. Actually slow downs a lot"
-             "the first optimization, and could possibly still contains some bugs."
+             "WARNING: work in progress, does not work yet. "
+             "Specify if the optimization cache should be used. This cache will "
+             "any optimized graph and its optimization. Actually slow downs a lot "
+             "the first optimization, and could possibly still contains some bugs. "
              "Use at your own risks.",
              BoolParam(False))

theano/gof/tests/test_fg.py

@@ -24,3 +24,8 @@ class TFunctionGraph(unittest.TestCase):
 
         s = pickle.dumps(func)
         func2 = pickle.loads(s)
+
+        vec = numpy.random.uniform(size=100)
+        assert func[vec] == func2(vec)
+
+