fix conflicting return type in getEvents
diff --git a/src/device-manager/cocoa/NLWdmClient.h b/src/device-manager/cocoa/NLWdmClient.h
index 8d59868..4a690fe 100644
--- a/src/device-manager/cocoa/NLWdmClient.h
+++ b/src/device-manager/cocoa/NLWdmClient.h
@@ -121,7 +121,7 @@
  * DataSchemaVersionRange | Object{MinVersion: uint64, MaxVersion: uint64}
  * Data                   | Object      | Event Trait Data
  */
-- (void)getEvents:(NSString **)events;
+- (WEAVE_ERROR)getEvents:(NSString **)events;
 
 
 @end