Removed customized wait method from throttles. This allows us to

send a x-throttle-wait-seconds header.

CHANGELOG.md

@@ -16,6 +16,8 @@ All notable changes to this project will be documented in this file.
 - allow more than one EMObservation subrow to be expanded at one time (#2605)
 - Changed name of "Duration" field in EMObservation form to "On source
   exposure" (#2603)
+- Removed customized wait method from throttles so that we can send an 
+    x-throttle-wait-seconds header to the user (#2457)
 
 ### Fixed
 - remove user from groups that are not present in IdP shibboleth assertion

gracedb/throttles.py

@@ -40,15 +40,6 @@ class PostOrPutUserRateThrottle(UserRateThrottle):
         self.cache.set(self.key, self.history, self.duration)
         return True
 
-    def wait(self):
-        """
-        The HTTPError exception includes a little message with the recommended
-        wait time. However, this doesn't seem to work very well with fractional
-        seconds. Returning 'None' will prevent it from trying to recommend a 
-        wait time.
-        """
-        return None
-
 class EventCreationThrottle(PostOrPutUserRateThrottle):
     scope = 'event_creation'