java_gen: support enum types, sets of enum types
diff --git a/java_gen/java_model.py b/java_gen/java_model.py
index a882475..bf74d82 100644
--- a/java_gen/java_model.py
+++ b/java_gen/java_model.py
@@ -736,6 +736,8 @@
             return self.enum_value
         elif java_type == "OFOxmList":
             return "OFOxmList.EMPTY"
+        elif re.match(r'Set.*', java_type):
+            return "Collections.emptySet()"
         elif re.match(r'List.*', java_type):
             return "Collections.emptyList()"
         elif java_type == "boolean":
@@ -1010,6 +1012,11 @@
             return java_type.u8
 
     @property
+    @memoize
+    def is_bitmask(self):
+        return any(ir_enum.is_bitmask for ir_enum in self.version_enums.values())
+
+    @property
     def versions(self):
         return self.version_enums.keys()