add event proxy

src/events.js

@@ -1,5 +1,14 @@
 export default class Events {
   constructor(art) {
     this.art = art;
+    this.destroys = [];
+    this.proxy = this.proxy.bind(this);
+  }
+
+  proxy(target, name, callback) {
+    target.addEventListener(name, callback);
+    this.destroys.push(() => {
+      target.removeEventListener(name, callback);
+    });
   }
 }