Restrict objects for testing equality

ipranges.py

@@ -26,8 +26,15 @@ class Range(object):
         return self.high() - self.low() + 1
 
     def __eq__(self, other):
-        if isinstance(other, (IPRangeBase, IPNetBase, IPAddrBase)):
-            return (self.low() == other.low() and self.high() == other.high())
+        if (
+            hasattr(self, "single")
+            and hasattr(other, "single")
+            and (
+                issubclass(self.single, other.single)
+                or issubclass(self.single, other.single)
+            )
+        ):
+            return self.low() == other.low() and self.high() == other.high()
         return False
 
     def __ne__(self, other):