1 files changed, 34 insertions, 0 deletions
diff --git a/ipapython/install/typing.py b/ipapython/install/typing.py
new file mode 100644
index 000000000..d86fc8f31
--- /dev/null
+++ b/ipapython/install/typing.py
@@ -0,0 +1,34 @@
+#
+# Copyright (C) 2016  FreeIPA Contributors see COPYING for license
+#
+
+import weakref
+
+import six
+
+_cache = weakref.WeakValueDictionary()
+
+
+class ListMeta(type):
+    def __getitem__(cls, key):
+        if not isinstance(key, type):
+            raise TypeError("Parameters to generic types must be types. "
+                            "Got {!r}.".format(key))
+
+        t = ListMeta(
+            cls.__name__,
+            cls.__bases__,
+            {
+                '__parameters__': (key,),
+                '__init__': cls.__init__,
+            }
+        )
+
+        return _cache.get(key, t)
+
+
+class List(six.with_metaclass(ListMeta, list)):
+    __parameters__ = ()
+
+    def __init__(self, *_args, **_kwargs):
+        raise TypeError("Type List cannot be instantiated; use list() instead")