a little faster with the optimizer

contracts/lib/Lib_MerkleTrie.sol

@@ -792,6 +792,7 @@ library Lib_MerkleTrie {
         bool isBytes
     )
         private
+        pure
         returns (
             TrieNode memory _node
         )

hardhat.config.js

@@ -9,10 +9,10 @@ module.exports = {
   solidity: {
     version: "0.7.3",
     settings: {
-      /*optimizer: {
+      optimizer: {
         enabled: true,
         runs: 200
-      }*/
+      }
     }
   },
 };