title: HowTo import core-js Map into angular-cli webpack generated application
body: <p>^1.0.0-beta.11-webpack&quot; now uses core-js for polyfills.</p>
  <p>I am trying to import a Map for use in my application</p>
  <pre><code>import {Map} from 'core-js/es6/map'
  //import {Map} from 'core-js/library/es6/map'
  
  export function updatePayload(data: any, isDataValid: boolean): Map&lt;string, any&gt; {
    const payload: Map&lt;string, any&gt; = new Map&lt;string, any&gt;()
    payload.set('data', data)
    payload.set('isDataValid', isDataValid)
    return payload
  }
  </code></pre>
  <p>I have even added the core-js d.ts file using</p>
  <pre><code>npm install --save @types/core-js (typescript 2.0 is used)
  </code></pre>
  <p>yet neither of the imports resolves the Map symbol.</p>
  <p>What am I missing?</p>
  <h3>EDIT 1 | Errors generated</h3>
  <p>I can now use the Map entity, but I am getting a lot of errors in the cosole, even though I can set/get map keys/values</p>
  <pre><code>client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:21:13 
  Duplicate identifier 'PropertyKey'.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:58:4 
  All declarations of 'name' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:118:4 
  Subsequent variable declarations must have the same type.  Variable '[Symbol.unscopables]' must be of type '{ copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: ...', but here has type 'any'.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:235:4 
  All declarations of 'flags' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:249:4 
  All declarations of 'EPSILON' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:284:4 
  All declarations of 'MAX_SAFE_INTEGER' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:291:4 
  All declarations of 'MIN_SAFE_INTEGER' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:430:4 
  Subsequent variable declarations must have the same type.  Variable '[Symbol.toStringTag]' must be of type '&quot;Symbol&quot;', but here has type 'string'.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:430:4 
  All declarations of '[Symbol.toStringTag]' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:437:4 
  All declarations of 'prototype' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:465:4 
  All declarations of 'hasInstance' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:471:4 
  All declarations of 'isConcatSpreadable' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:477:4 
  All declarations of 'iterator' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:483:4 
  All declarations of 'match' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:489:4 
  All declarations of 'replace' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:495:4 
  All declarations of 'search' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:501:4 
  All declarations of 'species' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:507:4 
  All declarations of 'split' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:513:4 
  All declarations of 'toPrimitive' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:519:4 
  All declarations of 'toStringTag' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:525:4 
  All declarations of 'unscopables' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:582:4 
  Subsequent variable declarations must have the same type.  Variable '[Symbol.toStringTag]' must be of type '&quot;Math&quot;', but here has type 'string'.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:582:4 
  All declarations of '[Symbol.toStringTag]' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:586:4 
  Subsequent variable declarations must have the same type.  Variable '[Symbol.toStringTag]' must be of type '&quot;JSON&quot;', but here has type 'string'.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:586:4 
  All declarations of '[Symbol.toStringTag]' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:601:4 
  All declarations of 'size' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:607:4 
  All declarations of 'prototype' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:618:4 
  All declarations of 'size' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:624:4 
  All declarations of 'prototype' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:639:4 
  All declarations of 'prototype' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:653:4 
  All declarations of 'prototype' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:665:4 
  All declarations of 'value' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\@types\core-js\index.d.ts:777:4 
  All declarations of 'prototype' must have identical modifiers.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  client:49 [default] J:\workspace\angular2\ts\epimss\node_modules\typescript\lib\lib.es2015.core.d.ts:17:13 
  Duplicate identifier 'PropertyKey'.errors @ client:49sock.onmessage @ client:83EventTarget.dispatchEvent @ eventtarget.js:51(anonymous function) @ main.js:274SockJS._transportMessage @ main.js:272EventEmitter.emit @ emitter.js:50WebSocketTransport.ws.onmessage @ websocket.js:35wrapFn @ zone.js:769ZoneDelegate.invokeTask @ zone.js:356Zone.runTask @ zone.js:256ZoneTask.invoke @ zone.js:423
  </code></pre>