fix: Update MISSING type

Charles Larivier · Charles Larivier · commit 89d957636037 · 2021-11-20T20:48:22.000-05:00
diff --git a/metabase/missing.py b/metabase/missing.py
@@ -1,6 +1,3 @@
 
-class MissingType:
+class MISSING:
     pass
-
-
-MISSING = MissingType()
