swarming: isolate defaults

appengine/swarming/server/task_request.py

Index: appengine/swarming/server/task_request.py
diff --git a/appengine/swarming/server/task_request.py b/appengine/swarming/server/task_request.py
index 744410bdd4cae7dff9c508be7bc42fbe5d6aa9bf..dc7eca1c68c1d8d6706aca36dfd1c8b10d880803 100644
--- a/appengine/swarming/server/task_request.py
+++ b/appengine/swarming/server/task_request.py
@@ -94,7 +94,7 @@ _BEGINING_OF_THE_WORLD = datetime.datetime(2010, 1, 1, 0, 0, 0, 0)
 
 # Used for isolated files.
 _HASH_CHARS = frozenset('0123456789abcdef')
-_NAMESPACE_RE = re.compile(r'^[a-z0-9A-Z\-._]+$')
+NAMESPACE_RE = re.compile(r'^[a-z0-9A-Z\-._]+$')
 
 
 ### Properties validators must come before the models.
@@ -125,7 +125,7 @@ def _validate_hostname(prop, value):
 
 
 def _validate_namespace(prop, value):
-  if not _NAMESPACE_RE.match(value):
+  if not NAMESPACE_RE.match(value):
     raise datastore_errors.BadValueError('malformed %s' % prop._name)