diff --git a/optimizely/optimizely_factory.py b/optimizely/optimizely_factory.py
index 5b7a879a..836d2981 100644
--- a/optimizely/optimizely_factory.py
+++ b/optimizely/optimizely_factory.py
@@ -34,9 +34,7 @@ def set_batch_size(batch_size):
         Args:
           batch_size: Sets size of event_queue.
          """
-
         OptimizelyFactory.max_event_batch_size = batch_size
-        return OptimizelyFactory.max_event_batch_size
 
     @staticmethod
     def set_flush_interval(flush_interval):
@@ -44,9 +42,7 @@ def set_flush_interval(flush_interval):
         Args:
           flush_interval: Time interval between event dispatches.
          """
-
         OptimizelyFactory.max_event_flush_interval = flush_interval
-        return OptimizelyFactory.max_event_flush_interval
 
     @staticmethod
     def set_polling_interval(polling_interval):
@@ -55,7 +51,6 @@ def set_polling_interval(polling_interval):
               polling_interval: Time in seconds after which to update datafile.
         """
         OptimizelyFactory.polling_interval = polling_interval
-        return OptimizelyFactory.polling_interval
 
     @staticmethod
     def set_blocking_timeout(blocking_timeout):
@@ -64,7 +59,6 @@ def set_blocking_timeout(blocking_timeout):
               blocking_timeout: Time in seconds to block the config call.
        """
         OptimizelyFactory.blocking_timeout = blocking_timeout
-        return OptimizelyFactory.blocking_timeout
 
     @staticmethod
     def default_instance(sdk_key, datafile=None):
@@ -98,8 +92,13 @@ def default_instance(sdk_key, datafile=None):
         )
 
         optimizely = Optimizely(
-            datafile, None, logger, error_handler, None, None, sdk_key, config_manager, notification_center,
-            event_processor
+            datafile=datafile,
+            logger=logger,
+            error_handler=error_handler,
+            sdk_key=sdk_key,
+            config_manager=config_manager,
+            notification_center=notification_center,
+            event_processor=event_processor
         )
         return optimizely
 
@@ -113,7 +112,6 @@ def default_instance_with_config_manager(config_manager):
     def custom_instance(sdk_key, datafile=None, event_dispatcher=None, logger=None, error_handler=None,
                         skip_json_validation=None, user_profile_service=None, config_manager=None,
                         notification_center=None):
-
         """ Returns a new optimizely instance.
              if max_event_batch_size and max_event_flush_interval are None then default batch_size and flush_interval
              will be used to setup BatchEventProcessor.
@@ -160,6 +158,14 @@ def custom_instance(sdk_key, datafile=None, event_dispatcher=None, logger=None,
         config_manager = config_manager or PollingConfigManager(**config_manager_options)
 
         return Optimizely(
-            datafile, event_dispatcher, logger, error_handler, skip_json_validation, user_profile_service,
-            sdk_key, config_manager, notification_center, event_processor
+            datafile=datafile,
+            event_dispatcher=event_dispatcher,
+            logger=logger,
+            error_handler=error_handler,
+            skip_json_validation=skip_json_validation,
+            user_profile_service=user_profile_service,
+            sdk_key=sdk_key,
+            config_manager=config_manager,
+            notification_center=notification_center,
+            event_processor=event_processor,
         )