Update packages/amino/src/secp256k1hdwallet.ts

Author: webmaster128

packages/amino/src/secp256k1hdwallet.ts

@@ -198,6 +198,8 @@ export class Secp256k1HdWallet implements OfflineAminoSigner {
   ): Promise<Secp256k1HdWallet> {
     const root = JSON.parse(serialization);
     if (!isNonNullObject(root)) throw new Error("Root document is not an object.");
+    // This cast is safe because `root` comes from a valid JSON document and `root` is a non-null object.
+    // I.e. it can only be a JSON object, not an aribitrary JS object.
     const untypedRoot: Record<string, any> = root;
     switch (untypedRoot.type) {
       case serializationTypeV1: {