fix prototype things

src/aragami.ts

@@ -34,10 +34,13 @@ export class Aragami {
     return 'default';
   }
 
-  private async getKey(o: any) {
+  private async getKey(o: any, prototype?: AnyClass) {
     if (typeof o === 'string') {
       return o;
     }
+    if (prototype) {
+      o = plainToInstance(prototype, o);
+    }
     const keyTransformer = reflector.get('AragamiCacheKey', o);
     if (!keyTransformer) {
       throw new Error(`No key metadata found for ${o.constructor.name}`);
@@ -125,7 +128,7 @@ export class Aragami {
   ) {
     return async (...args: A): Promise<T> => {
       const keyMeta = await keySource(...args);
-      const key = await this.getKey(keyMeta);
+      const key = await this.getKey(keyMeta, cl);
       if (!key) {
         return cb(...args);
       }