@@ -0,0 +1,538 @@
+#Reference from http://python-3-patterns-idioms-test.readthedocs.io/en/latest/Singleton.html%0A%0Aclass OnlyOne:%0A    class __OnlyOne:%0A        def __init__(self, arg):%0A            self.val = arg%0A        def __str__(self):%0A            return repr(self) + self.val%0A            %0A    instance = None%0A    def __init__(self, arg):%0A        if not OnlyOne.instance:%0A            OnlyOne.instance = OnlyOne.__OnlyOne(arg)%0A        else:%0A            OnlyOne.instance.val = arg%0A    def __getattr__(self, name):%0A        return getattr(self.instance, name)%0A%0A

Add singleton for python