title: How to unsubscribe from EventEmitter in Angular 2?
body: <pre><code>export declare class EventEmitter&lt;T&gt; extends Subject&lt;T&gt; {
      /**
       * Creates an instance of [EventEmitter], which depending on [isAsync],
       * delivers events synchronously or asynchronously.
       */
      constructor(isAsync?: boolean);
      emit(value: T): void;
      /**
       * @deprecated - use .emit(value) instead
       */
      next(value: any): void;
      subscribe(generatorOrNext?: any, error?: any, complete?: any): any;
  }
  </code></pre>
  
  <p>In Official Angular 2 Typescript definition, seems it has no way to mute or unsubscribe from EventEmitter.</p>
  
  <p>I got callback over time as pages use the same EventEmitter</p>