Create class after setting the class dictionary

Author: brandonwillard

pymc3/distributions/distribution.py

@@ -65,8 +65,6 @@ class _Unpickling:
 class DistributionMeta(ABCMeta):
     def __new__(cls, name, bases, clsdict):
 
-        new_cls = super().__new__(cls, name, bases, clsdict)
-
         # Forcefully deprecate old v3 `Distribution`s
         if "random" in clsdict:
 
@@ -94,6 +92,8 @@ def _random(*args, **kwargs):
 
             rv_type = type(rv_op)
 
+        new_cls = super().__new__(cls, name, bases, clsdict)
+
         if rv_type is not None:
             # Create dispatch functions