Add PcdCommitments::is_empty()

src/pcd.rs

@@ -225,6 +225,10 @@ impl PcdCommitments {
         Self(BTreeMap::new())
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
     pub fn update_with_value(&mut self, outpoint: &OutPoint, field: &str, new_value: &Value) -> Result<()> {
         let serialized_outpoint = serialize(outpoint);
         if let Some(old_hash) = self.get_mut(field) {