From 9d76adf7dfba192fb5b75d4254432bb6cd2bffff Mon Sep 17 00:00:00 2001
From: Noel Kwan <noelkwan1998@gmail.com>
Date: Mon, 3 Apr 2023 16:29:57 +0800
Subject: [PATCH] stub is_subset

---
 src/common/src/hash/key.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/common/src/hash/key.rs b/src/common/src/hash/key.rs
index 5a703d5ee336..51f7916ea3b2 100644
--- a/src/common/src/hash/key.rs
+++ b/src/common/src/hash/key.rs
@@ -67,12 +67,15 @@ impl NullBitmap {
     fn estimated_heap_size(&self) -> usize {
         8
     }
-    fn len(&mut self) -> usize {
+    fn len(&self) -> usize {
         self.inner.len()
     }
-    fn contains(&mut self, x: usize) -> bool {
+    fn contains(&self, x: usize) -> bool {
         self.inner.contains(x)
     }
+    pub fn is_subset(&self, other: &FixedBitSet) -> bool {
+        todo!()
+    }
 }
 
 /// A wrapper for u64 hash result.