feat: add batch_insert function

Cargo.toml

@@ -3,6 +3,9 @@ name = "pmtree"
 version = "0.1.0"
 edition = "2021"
 
+[features]
+batch_insert = []
+
 [dev-dependencies]
 hex-literal = "0.3.4"
 tiny-keccak = { version = "2.0.2", features = ["keccak"] }

src/tree.rs

@@ -188,6 +188,13 @@ where
         Ok(())
     }
 
+    /// Batch insertion, updates the tree in parallel.
+    /// Only available as a feature
+    #[cfg(feature = "batch_insert")]
+    pub fn batch_insert(&mut self, leaves: &[H::Fr]) -> Result<()> {
+        Ok(())
+    }
+
     /// Computes a Merkle proof for the leaf at the specified index
     pub fn proof(&self, index: usize) -> Result<MerkleProof<H>> {
         if index >= self.capacity() {