updated contents from Atlas repo

decorators/registration_param.py

@@ -0,0 +1,29 @@
+# BEGIN REGISTRATION_PARAM
+
+registry = set()  # <1>
+
+def register(active=True):  # <2>
+    def decorate(func):  # <3>
+        print('running register(active=%s)->decorate(%s)'
+              % (active, func))
+        if active:   # <4>
+            registry.add(func)
+        else:  # <5>
+            if func in registry:
+                registry.remove(func)
+
+        return func  # <6>
+    return decorate  # <7>
+
+@register(active=False)  # <8>
+def f1():
+    print('running f1()')
+
+@register()  # <9>
+def f2():
+    print('running f2()')
+
+def f3():
+    print('running f3()')
+
+# END REGISTRATION_PARAM