fix missed blanks

Author: Helene

source/metaclasses.py

@@ -20,9 +20,11 @@
 @author: HWASSMAN
 '''
 
+
 class Singleton(type):
     """metaclass to make a class a singleton"""
     _instances = {}
+
     def __call__(cls, *args, **kwargs):
         if cls not in cls._instances:
             cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)