refactor: don't extend Map for Context

packages/behavior/context/index.js

@@ -12,14 +12,18 @@ import * as Utility from './utility';
 const compiled = new Map();
 const debug = D('@avocado:behavior:context');
 
-class Context extends Map {
+class Context {
+
+  constructor() {
+    this.map = new Map();
+  }
 
   add(key, value) {
-    this.set(key, value);
+    this.map.set(key, value);
   }
 
   clear() {
-    super.clear();
+    this.map.clear();
     this.add('context', this);
     this.add('Flow', Flow);
     this.add('Math', MathExt);
@@ -38,7 +42,7 @@ class Context extends Map {
   }
 
   destroy() {
-    super.clear();
+    this.map.clear();
   }
 
   static renderSteps(steps) {
@@ -96,7 +100,7 @@ class Context extends Map {
         previousNode = node;
         return result;
       });
-    }, this.get(first.key));
+    }, this.map.get(first.key));
   }
 
   traverseOneStep(steps, previousNode, node, step) {

packages/physics/traits/collider.trait.js

@@ -65,8 +65,8 @@ export class Collider extends decorate(Trait) {
   pushActionBundle(paramActions, other) {
     const actions = behaviorItemFromJSON(paramActions);
     const context = createContext();
-    context.set('entity', this.entity);
+    context.add('entity', this.entity);
-    context.set('other', other);
+    context.add('other', other);
     const bundle = {
       actions,
       context,